Self-as-an-End
Self-as-an-End Theory Series · SAE Methodology Series · M-00

Methodology 00 Via Rho: The Way of the Remainder
方法论00 余之道 · Via Rho

Han Qin (秦汉)  ·  Independent Researcher  ·  2026
DOI: 10.5281/zenodo.19657440  ·  Full PDF on Zenodo  ·  CC BY 4.0
Abstract

This paper establishes Via Rho (the Way of the Remainder) as the methodological dual of Via Negativa. Methodology Paper VII systematized the apophatic tradition as a method of approaching Negativa through exclusion. This paper proposes Via Rho as its dual method: approaching Negativa by tracing the operative residue rather than by negating what it is not. The paper proceeds in three main movements. First, it establishes that Via Rho is walkable as a complete method, tracing the remainder backward to Negativa as the condition of all operation. Second, it establishes that the two via share a single limit-indication—they both point to the same Negativa though from opposite directions, each revealing different structural facets. Third, it presents the paper's central structural finding: at the operational level, Negativa and remainder exhibit an asymmetric mutual causation structure. Negativa supplies the existential condition of the remainder (ontological direction); the remainder supplies the dynamic condition of Negativa's continued operation (kinetic direction). The two directions hold in different modalities, which is why the causation is mutual but not symmetric. The asymmetric mutual causation is not a second axiom. It is a necessary corollary of Methodology Paper 0 at the operational level: Negativa is still the sole axiom, the remainder is still a theorem. What Methodology 00 contributes is a structural naming that makes explicit what was already implicit in Methodology 0—namely, that the two conservation results of Methodology 0 (the remainder is the product of not-negativa; the remainder drives the next operation) together form the asymmetric mutual causation structure. This paper borrows Heidegger's Gleichursprünglichkeit from Being and Time §28 as a philosophical term to support the structural claim, but with an explicit boundary: only the equiprimordial structural sense is retained; the symmetric sense of Heidegger's original usage is not. The borrowing is consistent with how Living-toward-Death (DOI: 10.5281/zenodo.18808585) borrows Sein zum Tode—taking the structural insight, not the full Heideggerian ontological commitment. Using the asymmetric mutual causation as an interpretive lens, the paper rereads three established structures in the SAE framework: the four phases of Methodology 0, the five cross-sections of the chisel-construct cycle in Methodology M, and the mutual non dubito structure at 16DD. Each rereading is a parallel perspective, not a replacement—the Methodology 00 reading runs alongside the original Methodology 0, M, and 16DD treatments without modifying them. The paper closes with an acknowledgement: why Negativa and the remainder exhibit this asymmetric mutual causation is a question structurally isomorphic to Methodology 0's "where does Negativa come from"—it is thing-in-itself territory. Methodology 00 neither answers nor evades this question; it marks the boundary. Main thesis: At the axiomatic level Negativa is sole; at the operational level Negativa and remainder are paired. ---

Keywords: Via Rho, Via Negativa, remainder, Negativa, asymmetric mutual causation, SAE methodology, operational level

Abstract

This paper establishes Via Rho (the Way of the Remainder) as the methodological dual of Via Negativa. Methodology Paper VII systematized the apophatic tradition as a method of approaching Negativa through exclusion. This paper proposes Via Rho as its dual method: approaching Negativa by tracing the operative residue rather than by negating what it is not.

The paper proceeds in three main movements. First, it establishes that Via Rho is walkable as a complete method, tracing the remainder backward to Negativa as the condition of all operation. Second, it establishes that the two via share a single limit-indication—they both point to the same Negativa though from opposite directions, each revealing different structural facets. Third, it presents the paper's central structural finding: at the operational level, Negativa and remainder exhibit an asymmetric mutual causation structure. Negativa supplies the existential condition of the remainder (ontological direction); the remainder supplies the dynamic condition of Negativa's continued operation (kinetic direction). The two directions hold in different modalities, which is why the causation is mutual but not symmetric.

The asymmetric mutual causation is not a second axiom. It is a necessary corollary of Methodology Paper 0 at the operational level: Negativa is still the sole axiom, the remainder is still a theorem. What Methodology 00 contributes is a structural naming that makes explicit what was already implicit in Methodology 0—namely, that the two conservation results of Methodology 0 (the remainder is the product of not-negativa; the remainder drives the next operation) together form the asymmetric mutual causation structure.

This paper borrows Heidegger's Gleichursprünglichkeit from Being and Time §28 as a philosophical term to support the structural claim, but with an explicit boundary: only the equiprimordial structural sense is retained; the symmetric sense of Heidegger's original usage is not. The borrowing is consistent with how Living-toward-Death (DOI: 10.5281/zenodo.18808585) borrows Sein zum Tode—taking the structural insight, not the full Heideggerian ontological commitment.

Using the asymmetric mutual causation as an interpretive lens, the paper rereads three established structures in the SAE framework: the four phases of Methodology 0, the five cross-sections of the chisel-construct cycle in Methodology M, and the mutual non dubito structure at 16DD. Each rereading is a parallel perspective, not a replacement—the Methodology 00 reading runs alongside the original Methodology 0, M, and 16DD treatments without modifying them.

The paper closes with an acknowledgement: why Negativa and the remainder exhibit this asymmetric mutual causation is a question structurally isomorphic to Methodology 0's "where does Negativa come from"—it is thing-in-itself territory. Methodology 00 neither answers nor evades this question; it marks the boundary.

Main thesis: At the axiomatic level Negativa is sole; at the operational level Negativa and remainder are paired.


Statement of Layers

This paper explicitly adopts an axiomatic-level / operational-level layering as its argumentative structure. At the axiomatic level Negativa is the sole axiom, not subject to modification; at the operational level Negativa and remainder together form the asymmetric mutual causation structure. The two levels are each true within their own jurisdiction, and the arguments of this paper hold within this layering.

This layering is a working assumption of Methodology 00, not an independently established fact. Whether a third level might be missed by this bipartite layering is not argued here. Should a third level exist, the scope of this paper's main thesis would need to be reconsidered. The exhaustiveness of the two-level layering is preserved as a structural remainder of this paper (see §8, Remainder One).

Placing this statement before the main text reflects a foundational-paper honesty requirement. Every specific argument in this paper depends on this layering; readers should see the layering's status as a working assumption before entering the specific arguments. This neither weakens the specific arguments (each still holds within the layering) nor conceals the arguments' dependency (the layering itself is explicitly marked as assumable).


1. From Negativa to Remainder · The Reversal of Path

Methodology Paper 0 (Negativa · On Negation Prior to Being) argued that Negativa is the sole axiom of SAE; everything else is theorem. It proceeded by the method of exclusion, chipping away at what Negativa is not, until only the self-referential double-negative manifestation remained. This was a direct indication of Negativa.

Methodology Paper VII (Via Negativa) took the exclusion method itself as the object of systematic treatment, inheriting the apophatic tradition. From Pseudo-Dionysius to Maimonides to Nicholas of Cusa, two millennia of negative sequences peeled away layer after layer, approaching the unnameable. Methodology VII distilled the operational rules of this method: the form of exclusion principles, the C4 injunction against sanctifying the remainder, the boundary signals of self-referential closure. Via Negativa became the first fully-formulated method of approaching Negativa within SAE.

But Via Negativa is not the only method.

Each operation of Negativa leaves a remainder. Methodology 0 itself argues this point. The remainder (ρ) is the product of not-negativa (negativa interrogating itself); remainder conservation is the naming of Negativa's structural incompleteness. The remainder is not an external axiom imposed on the system; it is the necessary companion of any operation of Negativa.

This means the remainder is always present. So long as Negativa operates, the remainder is being left. Conversely, wherever there is a remainder, there is the trace of Negativa in operation.

This opens a second methodological path. Rather than entering from the Negativa side (by excluding what Negativa is not), one can enter from the remainder side (by tracing the traces of Negativa's operation). Tracing the remainder is, in effect, returning to the condition under which Negativa operates. This path runs in the opposite direction from Via Negativa, starts from a different point, but takes the same Negativa as its limit-indication. Both paths anchor the same non-objectifiable condition.

Methodology VII bears Via Negativa. Methodology 00 proposes Via Rho (the Way of the Remainder) as the methodological dual of Via Negativa.

The relation between the two via is duality, not rivalry and not supplementarity. Rivalry would suggest that one is closer to the truth than the other; duality means they are two different ways of approaching the same truth. Supplementarity would suggest that each fills the other's gap; duality means each is complete in itself but enters from a different direction.

The completeness of Via Negativa is already established in Methodology VII. Methodology 00's task is to establish the completeness of Via Rho. If Via Rho is indeed a dual method, it must satisfy two conditions. First, it must be a complete path with a clear starting point (the remainder) and a clear limit-indication (Negativa). Second, the limit-indication it reaches must be the same Negativa that Via Negativa reaches, not some other limit-object.

These two conditions constitute the argumentative task of the first half of Methodology 00. §2 establishes the walkability of Via Rho. §3 establishes the equivalence of the two via—that they share the same limit-indication. Beginning in §4, the paper enters the content that Via Rho alone can reveal: namely, what the structure of Negativa's operation looks like when approached from the remainder side, and how this presentation differs from but does not contradict the Via Negativa presentation.

The existence of Via Rho is in fact already hinted at in the text of Methodology 0. §2 of Methodology 0 states that the remainder is the product of not-negativa; the same section states that the remainder drives the next operation. Taken together, these two statements amount to acknowledging that once the remainder appears, it enters a reciprocal relation with Negativa. Methodology 0 did not develop this reciprocal relation because its main axis was preserving the purity of Negativa as sole axiom. But this reciprocal relation has been waiting there to be taken up. Methodology 00 does so.

The paper's numbering carries this structure. Methodology 0 points directly at Negativa. Methodology VII takes up Via Negativa, the method of approaching Negativa, as an independent paper. Methodology 00 proposes Via Rho, the methodological dual of Via Negativa. The two zeros in "00" correspond to the two endpoints of the Via Rho path: the first zero is the starting point (remainder), the second zero is the limit-indication (Negativa). The "via" in the middle is the empty space that no character carries—yet it is precisely this empty space that constitutes the locus of Methodology 00's entire argument.

For the historical development of the methodology numbering system and possible future reorganization directions, see the appendix.


2. The Walkability of Via Rho

Methodology 00's first argumentative task is to establish the walkability of Via Rho. If one cannot, starting from the remainder, actually arrive (in the limit-indication sense) at Negativa, then Via Rho is not a path but a mere metaphor.

This section argues that Via Rho is walkable. The argument proceeds in four steps: the remainder has directionality (2.1); this directionality can be traced (2.2); tracing has Negativa as condition of operation as its limit-indication (2.3); the tracing does not diverge but continually structurally unfolds (2.4).

2.1 The Directionality of the Remainder

The remainder is not neutral. It is a trace, and a trace structurally points to what left it.

In everyday usage, a trace is always a trace of something—footprints are footprints of a walker, scratches are scratches from a tool, scars are scars from an injury. The trace's structural property is not its content but its pointing-back. Without what left it, a trace is not a trace but just a random mark.

The remainder carries the same structural property. ρ is the mark of Negativa's operation—the sign that an operation has taken place and that this operation was not complete. If one tries to imagine a remainder independent of the operation that produced it, what one has is not a remainder but just some arbitrary thing. Remainder-ness consists precisely in pointing back to the operation.

This directionality is not imposed from outside; it is constitutive of what the remainder is. Methodology 0 has already established this: the remainder is the product of not-negativa. To say the remainder is a product is to say it has a producer; to say it has a producer is to say it points back to that producer. The directionality is internal to Methodology 0's own argument.

2.2 Directionality Can Be Traced

Having directionality is one thing; being able to trace that directionality is another. Via Rho requires the second, not just the first. An arrow pointing somewhere you cannot follow is not a usable path.

Tracing a directionality means executing an operation on the remainder that asks after its origin. For the remainder ρ, this means: given ρ as trace, what operation could have left this trace? The asking is itself an operation. It is a Negativa-operation directed at ρ—a new application of Negativa, one that takes the remainder as its object of interrogation.

Here lies the critical point: this tracing operation does not require importing any external tool. It uses Negativa itself. The tracing of ρ's directionality is simply another operation of the same Negativa that left ρ in the first place. Via Rho is not a method that needs some external mechanism to be grafted onto SAE; it is a use of Negativa itself that has been available all along.

Methodology 0 provides the structural basis for this: Negativa cannot not operate. If an operation is possible on ρ, then Negativa will operate on ρ. Tracing is such an operation. Therefore tracing is not merely possible—it is structurally available whenever there is a remainder to trace.

2.3 The Limit-Indication of Tracing Is Negativa as Condition of Operation

What is the limit-indication of tracing? This is where Via Rho's walkability argument reaches its core.

Starting from ρ and asking "what operation left this?" one arrives at a specific Negativa-operation. But that operation itself produced its own ρ, and moreover was enabled by a prior state of Negativa. Tracing the first operation points to the conditions of that operation—and the deepest condition is the availability of Negativa itself as the ability to operate at all.

Here a potential confusion must be dissolved. Might tracing arrive at a specific instance of Negativa (this operation, that operation) rather than Negativa itself? In the SAE framework, Negativa is not a multiplicity of operations but the sole axiom that makes any operation possible. Operations of Negativa are particular events; Negativa itself is the condition under which such events occur. Specific operations can be indexed (op_0, op_1, etc.), but the subject of all these operations is the same Negativa—Negativa has no multiple instances.

With this understood, tracing the remainder is returning to this unified structure. It is not induction to multiple Negativae, nor the identification of some specific operation, but the return to the same non-objectifiable condition of operation. The tracing has as its limit-indication Negativa as the condition that makes all operations possible—the same condition that Methodology 0 posits as axiom directly, now structurally displayed through the tracing of remainders.

Two paths have the same Negativa as their limit-indication. Via Negativa points to Negativa by excluding what Negativa is not; Via Rho takes Negativa as condition of operation as its limit-indication by tracing the directionality of the remainder. Opposite directions, same limit-indication.

2.4 Tracing Does Not Diverge: Each Step Further Displays

Here a potential objection must be addressed in advance.

The act of tracing the remainder is itself a new operation of Negativa, and this operation necessarily leaves a new remainder. Tracing the new remainder is another operation of Negativa, leaving yet another remainder. On and on: tracing seems to lead to a divergent infinite recursion in which the tracer is forever generating new remainders and never reaching Negativa itself.

This objection is based on an intuition about recursive structures: recursion means divergence. But Via Rho's tracing recursion is not divergent; it is an approach-recursion anchored by the same non-objectifiable condition.

Immediately, a clarification is needed. Directly using "monotonically convergent sequence" as the mathematical term to describe Via Rho's recursion would introduce a hidden problem—"monotonic convergence" presupposes a metric space, presupposes measurable distance. But Negativa is non-objectifiable; it cannot be placed in a metric space as a measurable coordinate point. If one says "the new remainder is closer to Negativa than the old remainder," what is the metric of this "closer"? How is "distance" to a non-objectifiable limit-object defined? That road is a dead end.

Via Rho's recursive convergence structure is not distance-descent in a metric space; it is nested stripping in the sense of topological covering. A more precise expression: nested filter sequence.

The structure is as follows. Each act of tracing unfolds the prior remainder, allowing what had appeared only as first-order trace to disclose, through being interrogated, the deeper structure it was pointing to. The new remainder carries an additional layer of reflection on the conditions of the old remainder. The new remainder is not "one step closer in distance to Negativa"; rather, it has stripped away one layer of "apparent closedness" from the old remainder. The old remainder, as a trace, has a surface shell of closedness; interrogation strips this shell, disclosing the deeper structure the trace was pointing to—this is the new remainder. The new remainder has its own shell; the next interrogation strips further. Each interrogation is an act of topological stripping, not metric distance-shortening.

This structure can be made precise as follows: ρ_j has a higher order of display than ρ_i if and only if ρ_j explicitly contains the tracing mark of ρ_i's conditions of production. This is a structural partial order, not a metric distance. We do not say "ρ_j is closer to Negativa by some measurable amount"; we say "ρ_j displays one more layer than ρ_i." The partial order of display-order is the precise meaning of Via Rho's recursive convergence.

Another analogy. Tracing is like a series of nested filters. Each newly produced remainder is a finer filter, inheriting the structure of the previous filter but carrying one more layer of interrogation marks on the prior layer. The mesh becomes ever finer, but the filter is never what it is trying to separate—Negativa. We cannot measure how far we still are from Negativa; we only know that the mesh is monotonically fining. The fining of mesh is a structural act of stripping, not a shortening of spatial distance.

So tracing is not loitering at the same structural level; each step strips further toward deeper structure. Each interrogation lets the remainder more display the condition it points to—Negativa as condition of operation. This is not rhetorical "closeness"; it is structural "one more layer displayed"—the new remainder has one less layer of un-interrogated closedness and one more layer of exposure to production-condition.

This topological-stripping structure takes Negativa as its limit-indication. Via Rho's recursion is anchored by the same non-objectifiable condition. "Takes Negativa as limit-indication" is the precise expression of this anchoring—each step of the recursion displays more of this condition's operation-trace, but the condition itself (Negativa) cannot be captured as a coordinate point to be reached. The recursion never "reaches" Negativa as a possessible endpoint; it only displays, at each step, a further indication toward Negativa.

This also responds to Zeno-type objections. Zeno's Achilles-and-tortoise paradox assumes divergent recursion requires infinite time and cannot terminate. Via Rho's tracing recursion is not Zeno-type—it is not infinite approach at the same structural level but nested sequence of topological stripping. Each step is a structural act of stripping, not a crossing of distance. Zeno's paradox, in the Via Rho context, is not dissolved but found inapplicable—Zeno's assumption concerns distance-motion in a metric space, while Via Rho concerns structural nesting in topological stripping. The two differ in the structure of the problem itself.

Via Rho's peculiar character shows here. It is not a method of waiting for revelation (one negation suffices to arrive), nor a method expecting completion (the argument ends when the derivation ends). It is a method of sustained interrogation. Each interrogation leaves the interrogator structurally one layer more displaying of indication toward Negativa. It is true one never reaches a possessible endpoint (Negativa is non-objectifiable), but no step is wasted. Each tracing is an actual structural stripping, not repetition in place.

2.5 Summary

Via Rho is walkable. Starting from the remainder and tracing its directionality, recursively unfolding this tracing, at each step the new remainder displays more in the sense of topological stripping, taking Negativa as condition of operation as its limit-indication. This path requires no external tool; the tracing operation is internal to Negativa's own operation.

Nested filter sequence is the core of Via Rho's walkability. It ensures three things. First, each step of tracing is an act of structural stripping, not repetition in place. Second, the tracing recursion is anchored by the same non-objectifiable condition. Third, tracing takes Negativa as limit-indication—neither diverging infinitely nor reaching a possessible endpoint. These three together are the feasibility of Via Rho as method.

With walkability established, the next question is whether Via Rho's limit-indication and Via Negativa's limit-indication are the same Negativa, or are two different limit-objects. This is the task of §3.


3. The Equivalence of the Two Via

This section argues that the two paths have the same Negativa as their limit-indication. The argument is developed in three levels: reference identity, formal outline of dual-paths, and equivalence-not-replaceability.

3.1 Reference Identity

Via Negativa takes as its limit-indication Negativa as the unnameable, unknowable, unconstructable limit-object. This is the description carried jointly by Methodology 0 and Methodology VII.

Via Rho takes as its limit-indication Negativa as the common condition of operation of all remainders. This is the description established in §2.

Two descriptions point to the same object. The argument's crux is whether these two descriptions structurally co-refer within the SAE axiomatic structure.

"Unnameable, unknowable, unconstructable" limit-object: unnameable because naming is constructing and so is not possible; unknowable because knowing presupposes subject-object separation and subject-object separation is the result after Negativa has already operated; unconstructable because construct is the sediment of Negativa's operation, not Negativa itself. These three "un-" together give Methodology 0's negative definition of Negativa.

"Common condition of operation of all remainders": the condition that all remainders commonly indicate must itself be unnameable (if it had a name, the name itself would be a kind of construct; but it is the condition of construct, not a construct), must be unknowable (knowing means objectifying it, but it is the antecedent of subject-object separation and cannot be objectified), must be unconstructable (all constructs are products of its operation, not itself).

The three properties (unnameable, unknowable, unconstructable) of the two descriptions correspond one-to-one. This is not coincidence. The correspondence holds because the two descriptions refer to the same object, merely describing it from different angles. Via Negativa describes from the angle of "excluding what it is not," yielding the three "un-"s. Via Rho describes from the angle of "what the traces of its operation commonly indicate," yielding "common condition of operation." But for this common condition of operation to carry the role of what all remainders commonly indicate, it must be unnameable, unknowable, unconstructable.

The two descriptions structurally co-refer within the SAE axiomatic structure. Here the background premise of the argument must be made explicit—Methodology 0 has already argued two propositions: "Negativa is prior to 0DD" and "Negativa's operation necessarily leaves a remainder." Against this background, "the unnameable-unknowable-unconstructable limit-object" and "the common condition of operation of all remainders" refer to the same object. Specifically: the "unnameable-unknowable-unconstructable" as the negative definition of Negativa, combined with the Methodology-0-established proposition "Negativa's operation necessarily leaves a remainder," together necessarily entails "it is the condition that all remainders commonly indicate." Conversely, "the common condition of operation of all remainders" as a description of the remainder's indication-face, combined with the Methodology-0-established proposition "the remainder is the product of Negativa," together necessarily entails "this condition has a status more foundational than any product—that is, it is unnameable, unknowable, unconstructable."

To be clear: this co-reference is not a background-independent purely logical mutual entailment. It depends on the axiomatic structure Methodology 0 has already established. Outside this axiomatic structure, "unnameable-unknowable-unconstructable" and "common condition of operation of all remainders" could be interpreted as referring to different objects—many limit-objects can be described as unnameable-unknowable-unconstructable, but not all of them automatically become "common conditions of operation of remainders." So the argument here is "within the SAE axiomatic structure, the two descriptions structurally co-refer," not "in any philosophical framework, the two descriptions are logically mutually entailed."

So the two descriptions refer to the same object. Via Negativa and Via Rho take the same Negativa as their limit-indication.

3.2 Formal Outline of Dual-Paths

Reference identity is the philosophical argument of this section. A more formal outline can aid understanding this structure. The outline borrows the dual concept from category theory, but only for its structural intuition—not as strict proof.

Consider two limit-paths. Via Negativa's path starts from a sequence of negations "Negativa is not X," proceeding by layered exclusion toward the limit-object. Each item in the sequence is an excluded "not"; the sequence as a whole anchors Negativa at its limit. Via Rho's path starts from the remainder and follows its directionality of tracing, taking condition of operation as its limit-indication. Each item in the sequence is a new remainder; the sequence as a whole anchors Negativa as condition of operation at its limit.

The two paths run in opposite directions. One takes as its limit-indication the limit-object from the negative-description sequence; the other traces back from product-sequence to the common condition of the products. But they anchor the same non-objectifiable condition.

This structure corresponds in category theory to the general pattern of dual categories sharing a limit object, formally resembling the adjoint-pair structure. Left adjoint and right adjoint constitute a pair of functors in opposite directions, anchoring the same object at the limit. Via Negativa and Via Rho can be viewed as such a pair of opposite-direction approach processes, anchoring the same Negativa at the limit position.

A terminological note. In discussing adjoint-pairs, this section uses "endpoint" or "sharing their endpoint" as category-theoretic mathematical expressions—corresponding to terminal object or universal object in category theory, a structural-sense limit-position rather than a reachable coordinate point. This does not conflict with §2.4's established claim that "Negativa is non-objectifiable and cannot be reached as a coordinate point"—the latter is a claim at the SAE ontological level, the former is an expression at the mathematical-structural level. The two levels are each precise in their domain.

This paper uses this expression as heuristic isomorphism, not as strict category-theoretic proof. Strict formalization would require precise definitions of categories, objects, morphisms, adjoint functors, and other technical details—these are not Methodology 00's task. Methodology 00 borrows the structural intuition of adjoint-pair to obtain a formal outline, letting the intuition of "two paths in opposite directions sharing the same limit-indication" have a mathematical counterpart. Strict formalization is left to a subsequent mathematical appendix or independent paper.

This borrowing has one practical benefit. It lets readers unfamiliar with philosophical argumentation understand Methodology 00's basic claim via a known mathematical structure. Category-theoretically-trained readers see adjoint-pair and immediately understand that "opposite directions sharing a limit-indication" is a natural structure. Philosophically-trained readers can understand the same point through the familiar Via Negativa and the newly introduced Via Rho. The two training backgrounds meet here.

3.3 Duality at Different Levels

The two via are equivalent but do not replace each other. Equivalence means both paths have the same Negativa as their limit-indication. Not replacing each other means the ways in which they approach this limit-indication differ in structure, revealing different facets of Negativa.

The two via have a clear epistemological dual position. Via Negativa is an a posteriori approach; Via Rho is an a priori approach. Via Negativa starts from already-given constructs, excluding layer by layer; each step's work depends on the presence of already-available content; each exclusion presupposes that some construct at the phenomenal layer is first proposed and then negated. Via Rho does not start from phenomena; it starts from the a priori fact that the remainder is the necessary companion of Negativa's operation. "The remainder exists" is not an empirical observation; it is a structural feature of Negativa's operation itself. Tracing the remainder is tracing this a priori feature back to its position as antecedent condition of operation.

This a priori / a posteriori correspondence connects directly with the epistemological map of Methodology Paper II. Methodology Paper II established the 2×2 structure of cognitive operation: direction axis (a priori / a posteriori) × operation axis (synthesis / analysis), giving four quadrants of deduction, reduction, induction, abduction. Methodology II argues that none of the four quadrants can be stopped in—they must all be traversed—but it does not propose the traversal-process itself as a method. Methodology 00's contribution is to propose the two via explicitly as the methodological self-awareness of traversing the two axes. Via Negativa is the methodological self-awareness of traversing the a posteriori axis (induction and abduction quadrants); Via Rho is the methodological self-awareness of traversing the a priori axis (deduction and reduction quadrants). Together the two via cover the entire 2×2 map of Methodology II, constituting the complete methodological realization of the four-quadrant traversal Methodology II described.

Methodology 00 and Methodology II thus have deep duality. Methodology II discusses methodological movement at the subject level (the subject is pushed to traverse the four quadrants by the remainders); Methodology 00 discusses the structure at the operational-ontological level (Negativa operates, leaves the remainder, the remainder drives the next Negativa). The two are isomorphic: Methodology II's "remainders push the subject to traverse" and Methodology 00's "the remainder drives the next Negativa" are the same structure displayed at two description levels. Methodology II is Methodology 00 specified at the subject-cognitive level; Methodology 00 is Methodology II grounded at the operational-ontological level.

On this epistemological basis, the two via reveal different facets of Negativa.

Via Negativa reveals Negativa as limit. By excluding what Negativa is not, Via Negativa displays Negativa as the limit point of all "is-not"s. This limit is a static, unreachable, border-position existence. Negativa, from the Via Negativa perspective, is the common exterior of all exclusions, the residual position that no positive description can cover. This role corresponds mathematically to a topological limit—the unreachable boundary outside the closure.

Via Rho reveals Negativa as condition. By tracing the directionality of the remainder, Via Rho displays Negativa as the common condition of all operation. This condition is a dynamic, continuously-present, antecedent-position existence. Negativa, from the Via Rho perspective, is the source condition of all operation, the invisible support that every operation necessarily presupposes. This role corresponds mathematically to an analytic limit—the target value of sequence convergence.

The two "limits" are the same Negativa, but they play structurally different roles. The topological limit is the boundary of spatial structure; the analytic limit is the target of sequence convergence. Negativa simultaneously plays both roles. In Via Negativa, it is approached as topological limit (unreachable boundary); in Via Rho, it is traced as analytic limit (convergence target of sequence).

This structural difference makes the two via each irreplaceable.

The risk of using only Via Negativa is that Negativa displays as purely negative object, unnameable-unknowable-unconstructable nearly to the point of emptiness. Negativa as topological limit is precise but lacks a sense of presence. Readers might ask: what difference is there between this purely negative thing and nothingness? Via Negativa cannot answer directly; it can only continue by excluding "Negativa is not nothingness."

The risk of using only Via Rho is that Negativa displays as purely operational condition, approaching a kind of dynamic background. Negativa as analytic limit is present but might be misread as an entity-ized first cause. Readers might ask: what difference is there between this continuously-present condition and an original entity? Via Rho cannot answer directly; it can only handle this by emphasizing Negativa's non-objectifiability.

Together, the two via let readers see both Negativa's unreachability-as-limit (Via Negativa) and Negativa's continuous-presence-as-condition (Via Rho). Unreachability prevents Negativa from being entity-ized; continuous presence prevents Negativa from being void-ized. The two paths mutually defend against each other's possible misreading risks while revealing Negativa's dual structure.

This is the meaning of the two via as methodological duals. Not that one replaces the other, but that the two together carry the complete approach to Negativa. Methodology VII and Methodology 00 are each irreplaceable in the SAE methodology series.

3.4 ZFCρ as the Mathematical Carrier of Via Rho

The philosophical argument above establishes Via Rho as a dual method of Via Negativa at the methodological level. SAE's mathematical work has a corresponding realization: the ZFCρ series is the mathematical carrier of Via Rho.

ZFCρ's first paper (DOI: 10.5281/zenodo.18842458) argues a specific methodological fact: ZFC's extensional closure reduces operative acts to extensional artifacts, and this reduction leaves a ρ as structural cost. This ρ is not a defect of ZFC; it is what is paid for achieving extensional closure. ZFC cannot absorb ρ within its own axiomatic system because if it could absorb it, extensional closure would be compromised.

The structural relation between this ρ and Methodology 00's ρ is precise correspondence. Methodology 00's ρ is the remainder left by Negativa's operation—the necessary trace of the operation's incompleteness. ZFCρ's ρ is the remainder left by ZFC's extensional-closure operation—the necessary trace of this operation's incompleteness at the set-theoretic level. Both are the mark of an operation's incompleteness; both are tracked by Via Rho.

This correspondence is not coincidence. It is the concrete realization of Via Rho at the mathematical level. Methodology 00 proposes Via Rho as a method of philosophical-level tracking of the remainder. ZFCρ realizes this tracking at the set-theoretic level. The two work in the same direction, tracking the ρ left by a specific operation (Negativa's operation / ZFC's extensional-closure operation) to meta-level reveal what that operation is.

ZFCρ's three laws of chaos (ρ ≠ ∅, directionality, F(ρ) ≠ ∅) correspond directly to the three sentences of 0DD in Methodology 0 ("cannot not develop," "negation cannot terminate," "negation stops when it encounters the un-negatable"). This one-to-one correspondence is not an externally imposed analogy; it is the structural consistency between the mathematical-level Via Rho and the philosophical-level Via Rho. The same Via Rho method, applied to two layers, yields the same structural results.

This also explains a feature of the SAE methodological layout: why both Via Negativa as a philosophical method (carried by Methodology VII) and ZFCρ as mathematical work are needed. It is not because philosophy and mathematics are two independent disciplines each expanding independently; it is because Via Rho and Via Negativa as methodological duals must simultaneously expand in both disciplines. SAE uses Via Negativa in philosophical work (carried by Methodology VII); it uses the mathematization of Via Rho in mathematical work (carried by ZFCρ). The two work-lines are themselves a reflection of the methodological duality at the disciplinary level. Methodology 00's contribution is to explicitly propose the philosophical basis of this layout, letting Via Rho as an independent method obtain self-aware carriage at the methodological level.

3.5 Summary

Via Rho and Via Negativa take the same Negativa as their limit-indication. The argument unfolds in four levels: reference identity of the two descriptions (3.1), formal outline of dual-paths (3.2, heuristic isomorphism), the two via revealing different facets of Negativa at different levels (3.3, unreachable limit vs. continuously-present condition), and Via Rho's concretization at the SAE mathematical level (3.4, ZFCρ as the mathematical carrier of Via Rho).

Equivalence is established. Both paths anchor the same non-objectifiable condition. But equivalence does not mean replaceability: the two via reveal different structural facets of Negativa, each irreplaceable.

By this point, the first-half argumentative tasks of Methodology 00 are complete: Via Rho is walkable (§2), and Via Rho and Via Negativa are equivalent but reveal different structures of Negativa at different levels (§3). The second half of Methodology 00 enters the content that Via Rho alone can reveal: namely, what the structure of Negativa's operation presents when looked at from the remainder side.

This is the task of §4.


4. Asymmetric Mutual Causation · The Basic Finding of Via Rho

The first three sections established Via Rho as the methodological dual of Via Negativa. §2 argued Via Rho is walkable; §3 argued the two via take the same Negativa as limit-indication but at different levels reveal different facets of Negativa. These three sections established the legitimacy of Via Rho as an independent method.

Starting in §4, Methodology 00 enters the second half. This part's task is no longer to establish that Via Rho is walkable, but to present what Via Rho, walked as an independent method, reveals. Via Rho as an independent method reveals structures of Negativa that Via Negativa, in its own perspective, does not see. This is Methodology 00's central contribution as an independent work.

The central finding is asymmetric mutual causation.

4.1 Precise Definition of Asymmetric Mutual Causation

Mutual causation refers to a relation between two items A and B satisfying the following two conditions.

First, A cannot operate independently of B. A as operating subject requires B as the corresponding term of the operation. Without B, A's operation cannot proceed.

Second, B cannot exist independently of A. B as existing item depends on A's operation to be produced. Without A, B does not appear at any level of existence.

When these two conditions hold simultaneously, A and B are in a relation of mutual causation.

But this definition requires an immediate clarification. The modalities of the two conditions are different. The first condition speaks of the operational level (A cannot operate); the second condition speaks of the existential level (B cannot exist). The two conditions are not two symmetric faces of the same relation; they are two directions at different modalities.

This is asymmetric mutual causation. Symmetric mutual causation would require A and B to be mutually dependent at the same modality (for example, both cannot exist, or both cannot operate). Asymmetric mutual causation requires only that the two directions hold simultaneously at different modalities. Mutual causation's structural character consists in the two directions holding simultaneously; it does not consist in the two directions being at the same modality.

This asymmetry is one of the most critical clarifications in the paper. Without this clarification, readers would default to reading the mutual causation as symmetric, inferring from there that the two items have equal status. Under asymmetric mutual causation, A and B cannot at their respective modalities be independent of each other, but their ontological statuses are themselves not equal.

4.2 Negativa and Remainder Satisfy the Asymmetric Mutual Causation Definition

Substituting Negativa and remainder into the definition above.

Negativa cannot operate independently of the remainder. This is a direct corollary of the remainder conservation Methodology 0 has already argued. Methodology 0 argues that every operation of Negativa must be incomplete, and the incompleteness manifests as remainder. The most original operation is Negativa interrogating itself (not-negativa), and this operation produces the most original remainder. Any subsequent operation of Negativa inherits this structural incompleteness, leaving a remainder. Conversely, Negativa cannot operate without producing a remainder—there is no "pure Negativa-operation" with no accompanying remainder. So Negativa cannot operate independently of the remainder.

The remainder cannot exist independently of Negativa. This too is already argued in Methodology 0. The remainder is not an independent entity; it is the trace left by Negativa's operation. A trace ontologically depends on the operation that produced it—without the operation, there is no trace. The most original trace comes from not-negativa's original operation; any subsequent remainder is a trace of Negativa's operation. So without Negativa's operation there is no remainder appearing. The remainder cannot exist independently of Negativa.

Both conditions hold simultaneously. Negativa cannot operate independently of the remainder (operational-level direction); the remainder cannot exist independently of Negativa (existential-level direction). The modalities of the two directions differ. Negativa's direction concerns whether operation can proceed; the remainder's direction concerns whether existence can appear.

Negativa and remainder therefore satisfy the definition of asymmetric mutual causation.

This satisfaction is an integration of Methodology 0's content. Methodology 0 separately argued two things: the remainder is the product of not-negativa (negativa interrogating itself as the original operation), and the remainder drives the next operation of Negativa. These two arguments are placed in Methodology 0 to preserve the purity of Negativa as sole axiom—both arguments explain that the remainder is not an independent thing; all aspects of the remainder (origin and function) hang on Negativa. Methodology 00 combines these two arguments, seeing that together they are exactly the two directions of asymmetric mutual causation: the remainder comes from not-negativa (existential-level dependence); the remainder drives Negativa's continued operation (operational-level dependence). Methodology 0's argumentative results are not changed; only the structure they together display receives a new naming.

It is worth making one specific point explicit. The most original remainder is directly produced by not-negativa. Here a strict clarification is needed: this is not "most original" in the temporal sense, but "most foundational" in the logical-architectural sense. There is no "moment at which Negativa was isolated in stillness and had not yet produced a remainder." Negativa's axiomatic uniqueness is not temporal "priority" (prior in time) to the remainder but logical priority (ontological priority)—Negativa as sole axiom is the structural antecedent of what defines Negativa as Negativa, not the first moment in a temporal sequence.

The presence of Negativa is the presence of operation; the presence of operation is the presence of the remainder. When this paper says "the most original not-negativa produces the most original remainder," it describes the foundational form of the logical architecture, not the first second of a cosmic event. Time itself is a product of 3DD (Methodology 0 §8 already argues this); Negativa is prior to 3DD, so Negativa cannot be placed in a temporal sequence to speak of "before" and "after." Asymmetric mutual causation describes the structural simultaneity of what Negativa is as Negativa—Negativa and remainder are modally asymmetric (Negativa is source, remainder is trace) but absolutely co-present in manifestation (Negativa's presence is the remainder's presence).

All subsequent remainders share this foundational form. Each operation of Negativa leaving a remainder is a structural feature of Negativa as operation itself, not a feature that appears only at some stage of Negativa's unfolding. Asymmetric mutual causation is a structure that necessarily accompanies Negativa the moment operation begins. This foundational character secures asymmetric mutual causation's status as the basic structure of Negativa's operation, not merely as a relation that appears only under certain conditions.

4.3 Asymmetric Mutual Causation Is Not Accidental Pairing of Two Independent Components

This section guards against a possible misreading.

Mutual causation could be read as a special interdependence between two independent entities. On this reading, Negativa and remainder are two items each capable of independent existence, which happen to depend on each other under certain conditions. This reading makes asymmetric mutual causation look like a potentially-not-obtaining accidental relation—if conditions change, Negativa and remainder could each stand alone and the mutual causation relation would dissolve.

This reading is wrong.

Asymmetric mutual causation in the case of Negativa and remainder is not an accidental relation but a necessary one. This necessity comes from Methodology 0's remainder conservation. Methodology 0 argues that Negativa's operation is necessarily incomplete, and every incompleteness necessarily manifests as remainder. This necessity is not a necessity that holds only under some conditions; it is a structural feature of Negativa as operation itself. Negativa cannot "under some conditions operate completely" while "under other conditions operate incompletely"—Negativa is forever incomplete, forever leaving a remainder.

This necessity rules out the possibility of Negativa operating independently. A Negativa that could operate independently of a remainder would not be the Negativa Methodology 0 argues for; it would be something else. Methodology 0's Negativa is precisely the Negativa whose every operation must leave a remainder. So the asymmetric mutual causation of Negativa and remainder is not a relation between Negativa and remainder; it is a structural feature of Negativa as Negativa.

Conversely, the remainder is not something that depends on Negativa only under some conditions. The remainder just is the trace of Negativa's operation; the very concept of trace presupposes the producer of the trace. One cannot conceive of "a trace that does not depend on a producer"—that is not a trace but some other thing. So the remainder's dependence on Negativa is not a state of the remainder but a structural feature of the remainder as remainder.

Both sides together, the asymmetric mutual causation of Negativa and remainder is a structural feature of each being what each is, not an accidental relation between two independent entities. This necessity is the key guarantee of asymmetric mutual causation as Methodology 00's central finding. If mutual causation were merely accidental, Methodology 00 would only be describing a specific situation. Because mutual causation is necessary, what Methodology 00 reveals is the basic structure of Negativa in any operational situation.

4.4 The Relation Between Asymmetric Mutual Causation and Methodology 0's "Negativa Interrogates Itself"

One of the core arguments of Methodology 0 is that Negativa as sole axiom manifests through self-interrogation. Methodology 0 §2 unfolds this self-interrogation. Negativa interrogates Negativa itself, producing double negation, which produces the four phases. This is Methodology 0's basic move from Negativa to the four phases.

What is the relation between this core move of Methodology 0 and Methodology 00's asymmetric mutual causation? Are they two different structures or the same structure?

The answer is: the same structure manifesting at two levels. Negativa interrogating itself is the minimal unit of asymmetric mutual causation.

Specifically. When Negativa interrogates itself, the act of interrogation is itself an operation of Negativa. This operation has two participating items: Negativa as interrogator and Negativa as interrogated object. Both participating items are Negativa, but they play different roles in this interrogation. The interrogator performs the act; the interrogated object is established as the target.

The relation between these two roles is precisely the minimal unit of asymmetric mutual causation. The interrogator cannot operate independently of the interrogated object (without the interrogated object, the interrogation is empty). The interrogated object cannot exist independently of the interrogator's operation (without interrogation, there is no "interrogated object" position). The two directions are modally different—one is at the operational level (whether the interrogator can operate), the other at the existential level (whether the interrogated object can exist in the sense of being interrogated).

This is what it means to say that Negativa interrogating itself is the minimal unit of asymmetric mutual causation. The core move of Methodology 0 is not an independent special mechanism; it is the manifestation of asymmetric mutual causation in its most compact form.

This understanding brings two important consequences.

First, Methodology 00's asymmetric mutual causation is not an addition to or modification of Methodology 0. It is the structural naming of Methodology 0's core move. Methodology 0 uses the verbal phrase "Negativa interrogates itself" to refer to that core move. Methodology 00 uses the noun phrase "asymmetric mutual causation" to refer to the structure of the same move. Both refer to the same object; only Methodology 0, from the Via Negativa perspective, names it as an operational process, while Methodology 00, from the Via Rho perspective, names it as a structural relation.

Second, asymmetric mutual causation as the basic structure at the operational level is already established at the original position of Negativa interrogating itself. Methodology 0 develops the four phases from the interrogation; Methodology 00 develops the four phases from asymmetric mutual causation (§5's task). The two derivation chains handle different expansion directions of the same original structure. Methodology 0 unfolds it as the generation order of the four phases and the remainder; Methodology 00 unfolds it as asymmetric mutual causation's manifestation at different levels. The two expansions are complementary, not conflicting.

This section has made Methodology 00's relation to Methodology 0 clear. Methodology 00 does not add a new axiom, nor does it discover a new structure Methodology 0 did not see. Methodology 00 looks at the original move Methodology 0 has already unfolded, but from the Via Rho perspective, and gives this move a structural naming. The naming itself is Methodology 00's contribution—only with the naming can the subsequent sections of mutual-causation rereading (§5 on four phases, §6 on five cross-sections, §7 on 16DD) happen. Without the name "asymmetric mutual causation," these rereadings would have no conceptual handle.

At this point, asymmetric mutual causation as a concept has been established. The next subsections (4.5 to 4.7) enter formal expression, philosophical-term support, and the explicit handling of thing-in-itself reservation.

4.5 Formal Expression

The first four steps established asymmetric mutual causation as concept through prose. This step provides a formal expression, anchoring the concept in symbols.

The basic unfolding of asymmetric mutual causation can be written in the following form.

$$\mathcal{N} \xrightarrow{\text{op}_i} \rho_i \xrightarrow{\text{drive}} \mathcal{N} \xrightarrow{\text{op}_{i+1}} \rho_{i+1}$$

Here $\mathcal{N}$ is the unnameable indication of Negativa; $\text{op}_i$ is the $i$-th operation of Negativa; $\rho_i$ is the remainder (trace of incompleteness) produced by the $i$-th operation. Arrows express two different directions: $\mathcal{N} \xrightarrow{\text{op}_i} \rho_i$ is the ontological direction (Negativa's operation produces remainder); $\rho_i \xrightarrow{\text{drive}} \mathcal{N} \xrightarrow{\text{op}_{i+1}}$ is the kinetic direction (remainder drives Negativa's next operation).

The symbolic distribution of this formula itself encodes the asymmetry.

$\mathcal{N}$ has no subscript. No matter how many times $\mathcal{N}$ appears in the formula, it refers to the same Negativa. A subscript on $\mathcal{N}$ does not appear and need not appear—Negativa as sole axiom needs no version numbering. Each op acts on the same $\mathcal{N}$; there is no "the $i$-th Negativa" and "the $i+1$-th Negativa" as different versions.

What is subscripted is op (operation) and ρ (product). op has subscript $i$ because operations have ordinal-sense unfolding—the $i$-th operation and the $i+1$-th operation are different positions in the derivation sequence. ρ has subscript $i$ because each operation's remainder is distinguishable—$\rho_0$ is the most original remainder produced by the most original operation; $\rho_1$ is the remainder produced by the next operation; and so on. These remainders have their own specific trace-forms; they are not the same thing.

The asymmetric symbolic distribution ($\mathcal{N}$ without subscript, op and ρ with subscript) directly corresponds to the conceptual asymmetry. Negativa is a unified indication without subscript—the symbolic expression of axiomatic-level uniqueness. Remainder is a distinguishable trace with subscript—the symbolic expression of operational-level multiplicity. Operation is a specific event with subscript—the symbolic expression of operational-level unfolding. At a glance, the formula tells the reader: Negativa and remainder are not equal; one is a unified indication (no subscript), the other is a distinguishable product (with subscript).

The precise meaning of the subscripts must be made clear. Subscripts $i$ and $i+1$ are not markers of physical time; they are ordinal indices of logical derivation. Time itself is a product of 3DD (Methodology 0 §8 already argues this); Negativa is prior to 3DD, so Negativa's operation sequence cannot be understood as a temporal sequence. Interpreting subscripts as time would pull Negativa into the temporal structure, violating the structural fact that Negativa is prior to time. The correct understanding of subscripts is: they mark the depth of logical unfolding or the depth of fractal nesting, not the passage of time.

The same clarification applies to the arrows. The arrow $\mathcal{N} \xrightarrow{\text{op}_i} \rho_i$ is not a "Negativa then remainder appears" temporal-order relation. The arrow expresses the structural direction of asymmetric mutual causation: Negativa provides the existential condition of the remainder (ontological direction). This "providing" is not temporal before-and-after but structural dependence. $\rho$ structurally depends on $\mathcal{N}$ as its producing condition, and this dependence does not require temporal passage—it holds structurally at every unfolding of asymmetric mutual causation.

The starting-point state is at the position $i = 0$: $\mathcal{N} \xrightarrow{\text{op}_0} \rho_0 \xrightarrow{\text{drive}} \mathcal{N} \xrightarrow{\text{op}_1} \rho_1$. Here $\text{op}_0$ is the original operation of Negativa interrogating itself (i.e., not-negativa); $\rho_0$ is the original remainder produced by the original operation. This starting-point state corresponds to the foundational form discussed in §4.2—Negativa's axiomatic uniqueness and Negativa's operation are structurally simultaneously present; through $\text{op}_0$ as the original move, this manifests as a structurally co-present event (not a first moment in time).

Refinement of the Formalization: Distinction Between Construct and Remainder

The above formula expresses the basic structure of asymmetric mutual causation. But what op produces when it acts on $\mathcal{N}$ is actually not only ρ but also "construct" from Methodology M's five cross-sections. Construct and remainder are two different facets of the same action of op—construct is the sediment, remainder is the part the sediment cannot enclose. In Methodology M the two are independent cross-sections; Methodology 00 must preserve this independence.

The refined formula is written as follows.

$$\mathcal{N} \xrightarrow{\text{op}_i} (C_i, \rho_i) \xrightarrow{\rho_i \text{ drives}} \mathcal{N} \xrightarrow{\text{op}_{i+1}} (C_{i+1}, \rho_{i+1})$$

Here $C_i$ is the construct (sediment) produced by the $i$-th operation, and $\rho_i$ is the remainder (the part of the sediment that cannot be enclosed) left by the $i$-th operation. $C_i$ and $\rho_i$ are two products of the same action of $\text{op}_i$, not the same thing. The drive to the next operation comes from $\rho_i$, not from $C_i$—construct itself does not push the next operation; only the un-enclosed part of the construct (i.e., the remainder) pushes the next operation.

This refinement handles several things.

First, it prevents the "construct = ρ" misreading. The ρ in the basic formula only represents the remainder, not the construct. The construct gets an independent position in the refined formula. The five cross-sections of Methodology M include chisel, construct, and remainder as three different cross-sections; Methodology 00's formula must preserve this distinction.

Second, it lets Methodology 00's formalization connect directly with ZFCρ. ZFCρ's first paper argues that ZFC's extensional closure reduces operative acts to extensional artifacts, and this reduction leaves a ρ as structural cost. The $(C_i, \rho_i)$ in the refined formula precisely corresponds to this structure—$C_i$ is the extensional artifact (sediment), and $\rho_i$ is the operative trace that $C_i$ cannot absorb. The refined formula gives Methodology 00 and ZFCρ a symbol-level precise connection.

Third, it provides a formal handle for §6's rereading of the five cross-sections. §6 argues that the five cross-sections of the chisel-construct cycle are manifestations of asymmetric mutual causation at different granularities. In the refined formula, op corresponds to chisel (the operation itself), $C_i$ corresponds to construct (sediment), and $\rho_i$ corresponds to remainder (incompleteness). The bridge in the five cross-sections corresponds to the mechanism of transition from $\rho_i$ to $\text{op}_{i+1}$; thing-in-itself corresponds to the self-closure limit encountered in interrogating $\mathcal{N}$ itself. The refined formula gives §6's rereading a specific symbolic correspondence.

The basic formula $\mathcal{N} \xrightarrow{\text{op}_i} \rho_i \xrightarrow{\text{drive}} \mathcal{N} \xrightarrow{\text{op}_{i+1}}$ and the refined formula $\mathcal{N} \xrightarrow{\text{op}_i} (C_i, \rho_i) \xrightarrow{\rho_i \text{ drives}} \mathcal{N} \xrightarrow{\text{op}_{i+1}}$ each have their use. The basic formula is used when discussing the overall structure of asymmetric mutual causation (the focus of argument is the Negativa-remainder relation). The refined formula is used when discussing the correspondence between Methodology 00 and Methodology M's five cross-sections, and the connection with ZFCρ (the focus of argument is the construct-remainder distinction). The two-layer formulas run in parallel in Methodology 00; the latter does not replace the former.

On the Nature of This Formalization

An honest note is needed. The above formulas are not standard expressions inherited from some philosophical tradition; they are symbolic languages specifically coined by Methodology 00 for the asymmetric mutual causation structure. The structural inspiration comes from the formal shell of the general recursive relation $x_{n+1} = f(x_n)$ in mathematics, but the specific symbolic distribution ($\mathcal{N}$ without subscript, op and ρ with subscripts) and arrow-direction meaning are designed by Methodology 00 according to the structural features of asymmetric mutual causation.

In philosophical tradition there are partial counterparts, but each differs from Methodology 00's formula at a key point.

Hegel's thesis-antithesis-synthesis is a three-step recursive structure, but Hegel's three items are all content-bearing objects; each step unfolds new content, and synthesis is higher than both thesis and antithesis. Methodology 00's $\mathcal{N}$ is content-less; ρ is a structural trace not content; the next op still acts on the same $\mathcal{N}$, not on some higher synthesis. Methodology 00 does not take Hegel's spiral-ascent path.

Buddhism's twelve-link dependent origination (ignorance, volitional formation, consciousness... to old-age-and-death) is structurally the closest recursive precedent, but the twelve links are different items—each is an independent level of existence or psychological state. Methodology 00's $\mathcal{N}$ under each op is the same Negativa, not a linear unfolding through twelve different links. The twelve-link dependent origination needs external intervention (nirvana) to terminate; Methodology 00's recursion is internal, needing no external intervention.

Whitehead's process philosophy's bipolarity (physical pole and mental pole) has a certain source-structural quality, but both poles are active items. Methodology 00's $\mathcal{N}$ and ρ are asymmetric—$\mathcal{N}$ is source, ρ is trace.

Deleuze's Difference and Repetition has a "sameness unfolding through difference" structure, but Deleuze's position is that difference is prior to sameness; Methodology 00's position is that sameness (Negativa as sole) is prior to multiplicity (remainder as many). The directions are opposite.

Heidegger's Ereignis involves a mutual belonging of Being and Dasein, but Heidegger does not formalize this relation; he uses interpretive phenomenological description. Methodology 00 borrows Heidegger's Gleichursprünglichkeit as a specific term (see §4.6), not the entire thought-structure of Ereignis.

Listing these partial counterparts is not to seek family ties with philosophical traditions but to let readers see in what sense Methodology 00's formula is new. The formal shell (recursive structure) has precedents in both mathematics and philosophy; the asymmetric ontology ($\mathcal{N}$ source vs. ρ trace, one without subscript vs. one with subscript) is specifically designed by Methodology 00 according to the specific needs of the SAE framework.

Methodology 00 does not claim formalization itself is the main contribution. The main contribution is the structural finding of asymmetric mutual causation that the formalization expresses. Formalization merely anchors this finding precisely in symbols, for ease of discussion and verification.

A possible counter-question: does this formula simplify asymmetric mutual causation into a sequence? If it is a sequence, then it regresses into the temporal misreading. The response is this. The formula is a recursive relation, not a linear sequence. $\mathcal{N}$ under each op is the same Negativa, not different versions of Negativa. The subscripts of op and ρ mark the unfolding-position in the derivation sequence, not temporal coordinates. The "sequence" here is merely an expression tool used in the argumentation process to unfold the structure; it is not a linear temporal arrangement of $\text{op}_0, \text{op}_1, \text{op}_2$ in ontology.

The true meaning of this recursive relation is: asymmetric mutual causation unfolds completely in each op, and each unfolding is a re-manifestation of the same Negativa and the same mutual-causation structure. The operation sequence produces distinguishable remainders ($\rho_0, \rho_1, \rho_2$ differ from each other), but the structure of operation itself is unchanged. This is the most precise formal expression of Methodology 00's central finding.

4.6 Gleichursprünglichkeit and the Source-Primordial Character of Asymmetric Mutual Causation

The first five steps have established the concept and formalization of asymmetric mutual causation. This step gives asymmetric mutual causation a term support from philosophical tradition.

Negativa and remainder, at the operational level, exhibit Gleichursprünglichkeit (equiprimordiality).

Heidegger introduces this concept in Being and Time §28 to describe the relation between Dasein's worldliness (Weltlichkeit) and selfhood (Selbstheit). Two structures are equally primordial at the source level; neither can be reduced to being derived from the other. What Heidegger expresses with this German compound is a special ontological relation: two items are not sequential in appearance, nor derived one from the other; rather, at source they jointly appear as two faces of the same source-structure.

This paper borrows Gleichursprünglichkeit for its source-primordial structural sense. In the completed operational event, Negativa and remainder are inseparable—the two together constitute two faces of the same operational event, not divisible into two successive links. From §4.5's formula: without $\mathcal{N}$ there is no ρ (without Negativa's operation no remainder); but without ρ there is no next op (without remainder no continuation of operation). This inseparability is not a symmetric reading of "the two have equal status" (that would pull asymmetric mutual causation back into a symmetric original-principle misreading). At the level of condition-relation, Negativa still provides the existential condition of the remainder (ontological direction), and the remainder provides the kinetic condition of Negativa's continued operation (kinetic direction)—the two directions hold in different modalities. But in each completed operational event, the condition-giving in these two directions occurs simultaneously and inseparably—this is the precise meaning with which Gleichursprünglichkeit is borrowed.

An immediate clarification is needed: here Gleichursprünglichkeit is not original-principle symmetry but operational-level co-origination.

Heidegger's original sense discusses Dasein's structures' symmetric source-primordiality—worldliness and selfhood as two equal structural moments of Dasein, neither more primordial than the other. Methodology 00 discusses Negativa and remainder's asymmetric co-origination. Negativa still provides the existential condition of the remainder (ontological direction); the remainder provides only the kinetic condition of Negativa's continued operation (kinetic direction). The two directions hold at different modalities. Borrowing Heidegger's term borrows its source-primordial structural sense (the two are inseparable at the source level), not its two-side-symmetry (the two are of equal status).

The precision of this borrowing determines whether Methodology 00 can carry its central thesis. If Heidegger's symmetry were fully inherited, asymmetric mutual causation would be pulled back into a symmetric reading, and ρ would be elevated to original-principle status equal to Negativa. Methodology 00's entire argument would be overthrown. So the borrowing must have a boundary—borrow the source-primordial structural sense but not the symmetry.

A concurrent layering must be preserved: Gleichursprünglichkeit is a property at the operational level, not canceling Negativa as axiom's uniqueness. Negativa and remainder's Gleichursprünglichkeit holds at the operational level (the two inseparable in operation); Negativa's axiomatic uniqueness holds at the axiomatic level (Negativa is sole axiom, remainder is not a second axiom). Both levels each true, each precise in its own jurisdiction.

This layering corresponds to Methodology 00's central thesis: at the axiomatic level Negativa is sole, at the operational level Negativa and remainder are paired. Gleichursprünglichkeit is the philosophical-term support for the "Negativa-remainder paired" at the operational level. The axiomatic-level uniqueness and the operational-level pairing do not contradict, because they hold at different levels.

This paper borrows Gleichursprünglichkeit in a manner consistent with how Living-toward-Death (DOI: 10.5281/zenodo.18808585) borrows Sein zum Tode. Both borrowings take the structural sense of Heidegger's term to handle corresponding structures within the SAE framework; neither appropriates Heidegger's entire ontological commitment. The SAE series' overall stance toward Heidegger is selective absorption—borrowing the precise structural insights, not inheriting Heideggerian ontological commitments.

4.7 Why Asymmetric Mutual Causation Operates This Way: The Thing-in-Itself Reservation

By this point, Methodology 00's central thesis has been established: asymmetric mutual causation as the basic structure at the operational level; Negativa gives the existential condition of the remainder; the remainder gives the kinetic condition of Negativa's continued operation; the two have Gleichursprünglichkeit at the source level.

But there remains one question.

Why do Negativa and remainder have the asymmetric mutual causation structure and not some other relation? Why does Negativa necessarily produce a remainder? Why does the remainder necessarily drive the next Negativa? Where does the "necessity" of these necessities come from?

This question looks like a reasonable further probe of Methodology 00. If Methodology 00 could answer it, the argument would be more complete. But this probe actually touches the boundary Methodology 00 consciously carries.

This section argues: the question "why do Negativa and remainder have asymmetric mutual causation" is structurally isomorphic to Methodology 0's "where does Negativa come from." Methodology 00 takes up Methodology 0's handling—marking this as thing-in-itself level, neither answering nor evading.

The Structure of the Probe

The probe "why do Negativa and remainder have asymmetric mutual causation" presupposes one thing: that the asymmetric mutual causation structure itself can be probed to a deeper source. The probe seeks a thing more foundational than asymmetric mutual causation, a thing that could explain "why asymmetric mutual causation is this way and not some other way."

Methodology 0's "where does Negativa come from" is an isomorphic probe. It presupposes that Negativa can be probed to a deeper source, a thing more foundational than Negativa, which could explain "why Negativa is this way and not some other way."

The two probes have the same presuppositional structure: both seek an explanatory term more foundational than the current object.

Methodology 0 §8 has already argued that this kind of probe necessarily hits a wall at the position of Negativa. The reasoning is as follows.

Any probe requires direction. Seeking "a more foundational source" presupposes "foundationality" as a direction. Direction is a product of 3DD—space is 3DD, and directions in space are derivative structures of space. But Negativa is prior to 3DD—Negativa is at a position prior to 0DD, and 0DD is the common origin of 3DD (and all DDs). So "using direction to probe Negativa" is structurally impossible: one would be using Negativa's product (direction) to give direction to Negativa.

This is the concrete meaning of Methodology 0's "chisel hits chisel" and "the hammer hits the hammer, remaining intact." Thing-in-itself here manifests as the structural impossibility of the probe itself.

Isomorphic Probes Hitting Isomorphic Walls

The probe "why does asymmetric mutual causation operate this way" hits the same wall as the probe "where does Negativa come from."

Asymmetric mutual causation is the structure of Negativa as operation itself (§4.2 already argues this—Negativa cannot operate independently of the remainder, which is not a state of Negativa but a structural feature of Negativa as Negativa). So the probe "why does asymmetric mutual causation operate this way" is the probe "why is Negativa as Negativa the kind of Negativa that operates this way." Structurally, this probe is "why is Negativa Negativa"—which is the same wall as "where does Negativa come from," asked in a different form.

Methodology 0's handling is to mark the structural impenetrability of this wall. Methodology 00 takes up this handling. The question "why does asymmetric mutual causation operate this way" belongs to the thing-in-itself level; Methodology 00 neither answers nor evades, only marks that the wall Methodology 00 encounters at the source is the same wall Methodology 0 encounters.

This Is Not a Trick

A possible counter-response must be met head-on: that Methodology 00 is hiding the difficulty in a no-probe position, evading it. The specific form of this challenge might be: "You say asymmetric mutual causation is the basic structure, then say why it is so is thing-in-itself. Isn't this using the word 'thing-in-itself' to cover an empty argument?"

The response is as follows.

First, thing-in-itself is not a concept Methodology 00 introduces for itself. Methodology 0 has already established thing-in-itself as the wall the probe of Negativa necessarily hits. Methodology 00 takes up this pre-existing concept; it does not create it to evade difficulty.

Second, if Methodology 00 did not acknowledge this wall, it would do what Methodology 0 has already argued is impossible—use a product of Negativa to give direction to Negativa. Not acknowledging thing-in-itself is the real problem. Acknowledging thing-in-itself is a requirement of methodological honesty.

Third, acknowledging thing-in-itself does not cancel Methodology 00's argumentative work. Methodology 00 has argued that asymmetric mutual causation is the basic structure at the operational level (§4.2), argued that asymmetric mutual causation is not an accidental relation (§4.3), argued the relation between asymmetric mutual causation and Negativa interrogating itself (§4.4), given the formal expression (§4.5), given philosophical-term support through Gleichursprünglichkeit (§4.6). All this argumentative work is substantive; it provides substantive support for Methodology 00's central thesis. Thing-in-itself only marks a boundary; all the work within the boundary remains valid.

An argument that does not acknowledge thing-in-itself would instead have a logical problem—it would attempt to use Negativa's product to explain Negativa itself, producing circularity or infinite regress in the argumentative chain. Acknowledging thing-in-itself keeps Methodology 00's argumentation logically clean: argument unfolds fully where it can; honestly stops where it cannot.

A Collateral Understanding

Acknowledging thing-in-itself brings a collateral understanding.

Methodology 00 and Methodology 0 each encounter their own thing-in-itself; the two encounter the same wall (the same thing-in-itself). This is not coincidence. This is precisely another manifestation of Via Negativa and Via Rho as two dual paths both having the same Negativa as limit-indication—in their approach to Negativa, the two paths also encounter the un-probable character of Negativa being Negativa; this un-probability is Negativa's thing-in-itself character.

If the two paths encountered different things-in-themselves, it would mean they do not indicate the same object. That they encounter the same wall means they do indicate the same object. The identity of thing-in-itself is another manifestation, at the boundary, of the equivalence of Via Negativa and Via Rho (as §3 argues).

This collateral understanding makes the Methodology 00 / Methodology 0 boundary sharing not merely an argumentative technique ("acknowledge thing-in-itself to avoid a trick") but a structural fact ("two dual paths have the same Negativa as limit-indication so they encounter the same thing-in-itself"). Methodology 00 encountering thing-in-itself is neither failure nor evasion; it is a meeting with Methodology 0 at the same wall.

Summary

Asymmetric mutual causation is Methodology 00's central finding. Negativa provides the existential condition of the remainder (ontological direction); the remainder provides the kinetic condition of Negativa's continued operation (kinetic direction). The two directions hold at different modalities, constituting asymmetric mutual causation. Negativa and remainder at the operational level exhibit Gleichursprünglichkeit—co-origination but asymmetric. Why asymmetric mutual causation operates this way belongs to the thing-in-itself level; Methodology 00 neither answers nor evades.

Methodology 00 proposes asymmetric mutual causation at the operational level as a basic structural naming, taking up and making explicit Methodology 0's two argumentative results (remainder conservation and not-negativa producing the remainder). Methodology 00 does not add a new axiom or modify Methodology 0. It merely gives, from the Via Rho perspective, a structural naming to the original move Methodology 0 has already unfolded, so that the subsequent sections (four-phase rereading, chisel-construct-cycle rereading, 16DD deepening) have a conceptual handle.

This is the entirety of Methodology 00's central chapter. The following three sections (§5 to §7) display the explanatory power of this naming—using it to reread Methodology 0's four phases, Methodology M's chisel-construct cycle five cross-sections, and 16DD's mutual non dubito structure.


5. Rereading of the Four Phases Through Asymmetric Mutual Causation

Methodology 0 §2 derives the four phases from Negativa interrogating itself: Being, Non-Being, Neither-Being-Nor-Non-Being, and Neither-Not-Being-Nor-Not-Non-Being. Methodology 0's derivation follows the Via Negativa path—the four phases arise as products of interrogation through the exclusion of "what not-negativa is not."

This section rereads the four phases through asymmetric mutual causation. Each phase is a manifestation of asymmetric mutual causation at a specific level. This rereading does not replace Methodology 0's derivation; it supplements Methodology 0's derivation with a structural explanation from the Via Rho perspective. Together the two readings display different facets of the four phases.

5.1 The First Phase: Being as the First Manifestation of Asymmetric Mutual Causation

Being is the most original phase. In Methodology 0's derivation, Being arises when Negativa interrogating itself first produces something positive—the position of "there is something" emerges.

From the asymmetric mutual causation perspective, Being is the first manifestation of asymmetric mutual causation. The most original operation of Negativa (i.e., not-negativa, Negativa interrogating itself) produces the first remainder. This remainder appears positionally as Being. Being is not an independent substance; Being is the positional name of the first remainder produced by asymmetric mutual causation's first unfolding.

The asymmetry of mutual causation shows here. Negativa (as interrogator) and Being (as the first remainder) are not equal. Negativa is source; Being is trace. The two exhibit Gleichursprünglichkeit (in the first operational event they are inseparable) but not symmetric original-principle equality (Negativa is still the sole axiom, Being is the operational-level trace). This is asymmetric mutual causation's most compact manifestation—in one operation, the two-directional structure (ontological direction + kinetic direction) is fully displayed.

5.2 The Second Phase: Non-Being as the Asymmetric Mutual Causation Turnover of the First Phase

Non-Being is the second phase. In Methodology 0's derivation, Non-Being is produced when Negativa turns to interrogate Being—the result of negating Being.

From the asymmetric mutual causation perspective, Non-Being is the asymmetric mutual causation manifesting again at a new level, taking Being as object. The first operation produced Being; now the second operation takes Being as object of interrogation and produces a second remainder. This second remainder's positional name is Non-Being.

The turnover here is worth noting. The second operation's interrogated object is the first operation's remainder. The new remainder (Non-Being) is the trace of interrogating the old remainder (Being). So asymmetric mutual causation at the second phase has the first phase's product as interrogated object, displaying a layered structure—second-order mutual causation builds on first-order mutual causation.

5.3 The Third Phase: Neither-Being-Nor-Non-Being as the Asymmetric Mutual Causation Integration of Two Phases

The third phase is produced by Negativa interrogating the previous two phases together. In Methodology 0's derivation, Neither-Being-Nor-Non-Being arises when Negativa negates the dichotomy of Being and Non-Being, refusing to stop at either pole.

From the asymmetric mutual causation perspective, the third phase is asymmetric mutual causation's integration manifestation. The third operation takes not a single remainder but the relation between two remainders (the Being-Non-Being dichotomy) as object of interrogation. This produces a third remainder, whose positional name is Neither-Being-Nor-Non-Being.

The third phase handles integration—integrating Being and Non-Being as a relation. This integration is itself a manifestation of asymmetric mutual causation, but at a higher level of abstraction. The first two phases each had a single remainder as object; the third phase has the relation between two remainders as object. The abstraction level rises by one layer.

5.4 The Fourth Phase: Neither-Not-Being-Nor-Not-Non-Being as Asymmetric Mutual Causation Meeting Itself

The fourth phase is produced by Negativa interrogating the third phase itself. In Methodology 0's derivation, this is the self-referential closure—Negativa negating the negation of dichotomy, completing the argumentative loop.

From the asymmetric mutual causation perspective, the fourth phase is asymmetric mutual causation meeting itself. The third phase's remainder is already an integrated structure (integration of the Being-Non-Being relation). The fourth operation's interrogated object is this integrated structure itself.

The fourth phase's operation is further interrogation of this integrated state. But this interrogation encounters a situation the first three phases did not: the interrogated object has itself become an asymmetric mutual causation unit. The interrogations of the first three phases handled specific products—Being, Non-Being, the Being-Non-Being dichotomy—all specific products. The fourth phase's interrogation handles "the asymmetric mutual causation unit" as structure itself.

Interrogating an asymmetric mutual causation unit, the act of interrogation (Negativa) and the object of interrogation (an asymmetric mutual causation unit) mutually constitute each other's conditions. But the object of interrogation is itself already asymmetric mutual causation, so this co-origination is asymmetric mutual causation meeting asymmetric mutual causation—structure meeting structure.

This constitutes closure. The fifth interrogation's product is still an asymmetric mutual causation unit; continuing to interrogate is merely repetition within the same self-referential closed structure, producing no new content. The interrogation enters a structural self-loop.

So from the Via Rho rereading perspective, after the fourth phase no new structural type is produced. This does not mean speech cannot continue, nor that interrogation cannot continue—interrogation can continue, but its continuation is merely repetition within the same self-referential closed structure and does not produce independent new phases. Asymmetric mutual causation's unfolding completes these four steps and enters closure; the fourth phase's self-referential closure is precisely asymmetric mutual causation meeting itself.

A note on Methodology 00's stance here is worth making. Methodology 0 from the Via Negativa perspective has already argued for the closure of the four phases—the four phases exhaust all operational levels of "Negativa's action on itself," and the fourth phase's negation of negation brings about self-referential closure. Methodology 00's rereading from the Via Rho perspective is consistent with this conclusion of Methodology 0, merely looking at the same matter from a different angle—Methodology 0 looks at the exhaustion of interrogation-levels; Methodology 00 looks at the exhaustion of asymmetric mutual causation's unfolding-steps. The two perspectives are complementary, not conflicting. Methodology 00 does not reprove a stronger four-phase theorem than Methodology 0; it only provides, from the Via Rho perspective, a structural explanation for the same closure conclusion.

5.5 The Four Phases as Complete Self-Display of Asymmetric Mutual Causation

Taking the four phases together.

The first phase is the first manifestation of asymmetric mutual causation (producing the first remainder, Being).

The second phase is asymmetric mutual causation's turnover taking the first remainder as object (producing the second remainder, Non-Being).

The third phase is asymmetric mutual causation's integration taking the relation between two remainders as object (producing the third remainder, Neither-Being-Nor-Non-Being).

The fourth phase is asymmetric mutual causation's self-encounter taking the integrated structure itself as object (producing self-referential closure, Neither-Not-Being-Nor-Not-Non-Being).

Levels rise layer by layer. The first phase handles no prior remainder (directly produces the first one). The second phase handles one prior remainder. The third phase handles the relation between the first two remainders. The fourth phase handles the structure of integration itself. The object of interrogation becomes progressively abstract, and at the fourth level encounters structure itself's self-reference.

This level-ascent corresponds to Methodology 0's "four phases advance layer by layer." Methodology 00's contribution is to give the "layer by layer" structural feature a precise description—each layer is a manifestation of asymmetric mutual causation, but the manifestation's object becomes progressively abstract in level, finally encountering structure itself's self-reference at the fourth level.

5.6 A Collateral Observation

This level-ascent insight connects Methodology 00 with the rereading of the chisel-construct cycle's five cross-sections in §6. The five cross-sections are also a layer-by-layer unfolding structure, and the four phases' layering corresponds to the chisel-construct cycle's more general layer-by-layer unfolding. §6 will further develop this connection.


6. Rereading of the Chisel-Construct Cycle Through Asymmetric Mutual Causation

Methodology M (the Methodological Overview) derives from 0DD to 16DD, establishing the chisel-construct cycle as SAE's basic unit of motion. The five cross-sections of the chisel-construct cycle are chisel, construct, remainder, bridge, and thing-in-itself. Methodology M's derivation follows the Via Negativa path—through the exclusion of the necessary unfolding that follows from "Negativa as sole axiom," it derives the five cross-sections and the 16-level dimension sequence.

Methodology 00 rereads the five cross-sections. From the Via Rho perspective, the five cross-sections are manifestations of asymmetric mutual causation at different granularities. This section's task is to display this rereading, explaining how asymmetric mutual causation unifies the structure of the five cross-sections.

The positioning of this section must be declared clearly in advance. The asymmetric-mutual-causation reading of the five cross-sections in this section is a parallel perspective, not a replacement of Methodology M. Methodology M names the five cross-sections from the unfolding face of Via Negativa; Methodology 00 sees their shared dynamics from the retrospective face of Via Rho. Both perspectives hold simultaneously; Methodology M is not modified by Methodology 00's rereading. The five cross-sections as working language of the chisel-construct cycle are established in Methodology M; Methodology 00 only points out the structural interpretation this working language obtains from the Via Rho perspective.

6.1 Chisel and Construct as a Pair of Facets of Asymmetric Mutual Causation

Chisel is the action of negation; construct is the sediment of negation. Methodology M argues that chisel and construct mutually transform each other in the chisel-construct cycle—each chisel leaves a construct as sediment, and each construct's incompleteness emerges to summon a new chisel.

From the asymmetric mutual causation perspective, chisel and construct are a pair of facets of asymmetric mutual causation, but the way this pair is constituted requires precise specification.

Chisel is the face of Negativa in the mutual causation (performing the operation of negation). Chisel as action corresponds to $\text{op}_i$ in §4's formal expression—the chisel-operation is the operation of Negativa; chisel is Negativa's specific-action manifestation.

Construct is the sediment left by Negativa's operation, corresponding to $C_i$ in the refined formula. Remainder is the part of this sediment that cannot be enclosed, corresponding to $\rho_i$. Each chisel-operation simultaneously produces construct and remainder, but construct is not itself remainder—construct is the sediment itself; remainder is the un-enclosable part of that sediment. The incompleteness of construct manifests as remainder. The two are cognate but not identical. Methodology 00 in §4.5's refined formula explicitly separates the two: $\mathcal{N} \xrightarrow{\text{op}_i} (C_i, \rho_i)$, where $(C_i, \rho_i)$ are two products of $\text{op}_i$'s single action, not the same thing.

Chisel and construct are not two independent cross-sections in accidental pairing; they are two facets of the same asymmetric-mutual-causation operation. Without chisel there is no construct (without the action of negation there is no sediment), corresponding to Negativa's giving of the existential condition of the remainder in asymmetric mutual causation. Without construct there is no field in which remainder can manifest—remainder is the part the construct cannot enclose, so the appearance of remainder requires construct's existence as condition. Without remainder there is no driving force for the next chisel—strictly speaking, what pushes the next chisel is not construct itself but the remainder that construct exposes. This corresponds to the remainder's giving of the kinetic condition of Negativa's continued operation in asymmetric mutual causation.

Methodology M uses the term "chisel-construct cycle" to describe the sustained motion of this pair of facets. Methodology 00 points out that the internal structure of this cycle is precisely asymmetric mutual causation—chisel (i.e., op) acting on $\mathcal{N}$ produces the pair of products construct and remainder, and remainder drives the next chisel. Chisel and construct are asymmetric in status (chisel is the source operation, construct is the sediment), and construct and remainder are also asymmetric in status (construct is the product, remainder is the un-enclosable part of the product). The entire cycle unfolds continually through the kinetic direction of the remainder.

6.2 Remainder as the Kinetic Term of Asymmetric Mutual Causation

Remainder (ρ) is Methodology M's third cross-section. Methodology M argues that remainder is not a simple by-product of chisel and construct; it has an independent status—remainder is the driving force that drives the next chisel. The conservation of remainder (ρ ≠ ∅) guarantees the chisel-construct cycle never terminates.

From the asymmetric mutual causation perspective, the reason for remainder as independent cross-section becomes clear. Remainder carries the direction "the remainder gives the kinetic condition of Negativa's continued operation" in asymmetric mutual causation.

Here remainder and construct need to be distinguished. Both are products of Negativa's operation, but they carry different structural roles.

Construct is the "sediment" after the negating operation sediments, the direct output of the operation. As a cross-section, construct describes "what the chisel-operation produced"—the answer is construct, this product.

Remainder is the "incompleteness trace" of the negating operation, a structural feature of the operation. As a cross-section, remainder describes "what part the chisel-operation cannot complete"—the answer is remainder, this incompleteness.

From the refined formula $\mathcal{N} \xrightarrow{\text{op}_i} (C_i, \rho_i)$ in §4.5, construct $C_i$ and remainder $\rho_i$ are two different products of $\text{op}_i$'s single action. The two are cognate (same operation) but different things (one is the sediment itself, the other is the un-enclosable part of the sediment). The same op produces both because Negativa's operation is necessarily incomplete—the operation leaves sediment (this is construct) and simultaneously leaves incompleteness (this is remainder). The two are not two facets of the same thing; they are two parallel products of the same action.

Remainder as independent cross-section has a special status (Methodology M argues "remainder has direction, construct has no direction") precisely because it carries the kinetic role of asymmetric mutual causation. Construct has no direction because construct is only a sediment; sediment itself does not point in any direction. Remainder has direction because remainder is the part construct cannot enclose; the state of not being enclosable itself points toward the next operation—this "pointing toward the next" is direction.

6.3 Bridge as the Local Excitation of Asymmetric Mutual Causation

Bridge is Methodology M's fourth cross-section. Methodology M argues that bridge is the local event in which remainder accumulates to a critical point and forces the chisel to operate again. Bridge is not a sustained process but a moment of excitation—the leap from the current state to the next chisel.

From the asymmetric mutual causation perspective, bridge is the processual manifestation of asymmetric mutual causation.

Asymmetric mutual causation as basic structure contains the direction "the remainder gives the kinetic condition of Negativa's continued operation." But this "continued operation" in concrete unfolding is not continuous—remainder must accumulate to a certain degree before it excites the next chisel. This moment of excitation is the bridge.

Bridge corresponds in §4.5's formal expression to the step from $\rho_i$ to $\text{op}_{i+1}$—the transition from the current remainder to the next Negativa-operation. But that step in the formal expression is an abstract expression; in concrete operation this step is completed through the specific event of bridge. Bridge gives the abstract transition in the formula a concrete mechanism.

This makes the necessity of bridge as an independent cross-section clear. Without bridge as a cross-section, the kinetics of the chisel-construct cycle would be incomplete—it could only say "the remainder drives the next chisel," not "how the remainder drives the next chisel." Bridge fills in this "how" concrete mechanism.

6.4 Thing-in-Itself as the Self-Closure Limit of Asymmetric Mutual Causation

Thing-in-itself is Methodology M's fifth cross-section. Methodology M argues that thing-in-itself is the wall the chisel-construct cycle encounters when it tries to probe its own source.

From the asymmetric mutual causation perspective, thing-in-itself is the self-closure limit of asymmetric mutual causation.

Asymmetric mutual causation can be infinitely unfolded at the operational level—op after op, remainder after remainder, the cycle can continue forever. But when asymmetric mutual causation turns to probe its own source (why does asymmetric mutual causation operate this way), it encounters the wall §4.7 has already argued. This wall is the self-closure limit of asymmetric mutual causation—the operational-level unfolding cannot reach the structure's own source.

Methodology M names this wall the thing-in-itself, making it the fifth cross-section of the chisel-construct cycle. This is not adding an external cross-section; it is the consciousness of the cycle's own limit. Asymmetric mutual causation's self-closure at the source is the thing-in-itself cross-section's structural basis.

6.5 The Five Cross-Sections as Manifestations of Asymmetric Mutual Causation at Different Granularities

Taking the five cross-sections together.

Chisel is asymmetric mutual causation as operation itself (op).

Construct is the sediment of asymmetric mutual causation's operation ($C$).

Remainder is the trace of asymmetric mutual causation's operational incompleteness ($\rho$).

Bridge is the processual excitation mechanism of asymmetric mutual causation (from $\rho_i$ to $\text{op}_{i+1}$).

Thing-in-itself is the self-closure limit of asymmetric mutual causation when probing its own source.

The five cross-sections exhibit asymmetric mutual causation at different granularities. Chisel displays the single-step action (granular). Construct displays the direct output of action (product). Remainder displays the structural feature of action (incompleteness). Bridge displays the transition mechanism from the current step to the next step (processual). Thing-in-itself displays the structural boundary of the entire action (limit). Five granularities together constitute the complete unfolding of the chisel-construct cycle.

This granularity structure explains why the five cross-sections are exactly five, not some other number. Each granularity level has its structurally necessary content—none can be merged with another, none is superfluous. Methodology M derives the five cross-sections through Via Negativa's exclusion unfolding; Methodology 00 rereads them through Via Rho's asymmetric mutual causation granularities. The two derivations arrive at the same result, displaying the internal consistency of the SAE framework.

6.6 The Value of the Rereading

Why does Methodology M already having derived the five cross-sections still need Methodology 00's rereading?

The rereading's value is not to add new content but to provide a structural explanation. Methodology M derives the five cross-sections as working language of the chisel-construct cycle, but Methodology M itself does not explicitly unify the structural relations between the cross-sections. Readers of Methodology M know "the five cross-sections are the five components of the chisel-construct cycle," but they may still be unclear about "why exactly these five are a whole." Methodology 00's rereading gives this "why a whole" an answer: the five cross-sections are asymmetric mutual causation's manifestations at five different granularities; the structure asymmetric mutual causation carries has, at each granularity level, its structurally necessary correspondence.

This rereading thereby makes the SAE framework more internally consistent. The five cross-sections of Methodology M and the asymmetric mutual causation of Methodology 00 are two perspectives on the same structure. Readers can use either language. Those wanting concrete operation can use the five-cross-section language to discuss chisel, construct, remainder, bridge, and thing-in-itself. Those wanting structural understanding can use the asymmetric-mutual-causation language to discuss how the five cross-sections unify at the structural level.

Methodology M and Methodology 00 therefore relate as complementary, not competitive. Methodology M provides the work; Methodology 00 provides the interpretation. The two together let the chisel-construct cycle have both operable concrete tools and intelligible structural foundations.


7. Further Deepening of 16DD

16DD has already undergone multiple deepenings in the SAE series.

Methodology 0 §7 did the first deepening on 16DD, elevating mutual non dubito from interpersonal ethical description to the ontological level: 16DD is not the endpoint or limit of Negativa but the encounter of two Negativae. Each subject is the manifestation of a Negativa at the unfolding sequence's terminal; the two meeting is the collision of two Negativae. This is Methodology 0's first ontological elevation of 16DD.

Methodology 00 does further deepening. From the asymmetric mutual causation perspective, the two subjects' encounter is not the collision of two Negativae (this would still stay at the level of two simple entities), but the meeting of two asymmetric mutual causation units. This is the second deepening.

7.1 The Double Role of the Remainder at the Level Layering

The first point this deepening requires is distinguishing the role of the remainder at different DD levels.

In the range of 1DD to 15DD, remainder as kinetic term drives Negativa's next operation. This is the role $\rho_i$ carries in §4's asymmetric-mutual-causation formal expression—$\rho_i$ drives $\mathcal{N}$ into the next operation $\text{op}_{i+1}$. Remainder here is functional; its role is to let Negativa's operation continue.

But at the specific position of 16DD, remainder changes role.

16DD is the position of two subjects encountering. Each subject is an asymmetric mutual causation unit. In this encounter, the "remainder-ness" of one subject (A) to the other (B) is no longer the kinetic-term remainder-ness (A is not B's driving force of operation) but a special existential-level remainder-ness (A is what B's operation cannot enclose as outside).

This is what the paper calls "ontological remainder"—remainder in the sense of ontological externality, not in the sense of kinetic trace.

This distinction is important because it prevents a potential ethical crisis. If 16DD's "mutual remainder" were read as remainder in the 1DD-to-15DD sense (kinetic term), then subject A would become the driving force of subject B's operation, meaning A is used by B as tool. This directly violates the SAE ethical proposition (the human is end, not tool).

The concept of ontological remainder prevents this crisis. At the 16DD position, the two subjects being each other's remainder is in the sense of un-enclosable externality, not in the sense of kinetic term. The two subjects, precisely because they cannot enclose each other, must recognize each other as end. Remainder here equals the ontological premise of end-itself.

7.2 Ontological Restatement of Mutual Subject-Causation

With the double role of the remainder at the level layering as premise, we can restate 16DD's asymmetric mutual causation structure.

Two subjects mutually recognize each other as end-itself. This "mutual" is the complete realization of asymmetric mutual causation at the inter-subject level. But to understand the precise meaning of this "mutual," one must see its structure clearly.

Subject A is an asymmetric mutual causation unit. Negativa (A's chisel-construct cycle's operation) gives the existential condition of remainder (the incompleteness produced by A's construct); remainder gives the kinetic condition of Negativa's continued operation. A as a complete unit unfolds continuously in its own operation sequence.

Subject B is another asymmetric mutual causation unit. The same internal structure. B unfolds continuously in its own operation sequence.

What happens when the two units encounter.

A as a unit whole appears in B's cognitive view. B recognizes A as a subject—not as an object B can process, but as a complete asymmetric mutual causation unit. In this recognition, A as whole is not a product B's internal construct can generate. A structurally exceeds the range that B's construct can enclose.

A key precisification is required here. B not being able to enclose A is not a matter of B's cognitive capacity being insufficient. If it were understood as a cognitive capacity matter (for example, B's construct being not complete enough or strong enough to process A), 16DD's encounter would be downgraded to the level of cognitive failure—A's independence would depend on B's capacity being inadequate, and once B's capacity became sufficient it could enclose A. This reading would hollow out 16DD's ethical significance.

The precise understanding is as follows. A as a complete asymmetric mutual causation unit, its ontological status does not depend on whether B can place it into B's own construct. However complete B's construct is, this does not change A's ontological fact as an independent asymmetric mutual causation unit. "B cannot enclose A" is a structural fact at the ontological level—no matter how complete B's construct is, none of B's constructs is at the position of A as an independent mutual causation unit. A's position is A itself. B's position is B itself. The independence of the two positions is not a matter of B not reaching A (that would be a capacity matter) but a matter of none of B's constructs being at the position of A (that is an ontological matter).

This precisification ensures that the 16DD encounter is at the ontological level, not at the cognitive level. A and B mutually cannot enclose each other because the two as two independent asymmetric mutual causation units just are so, not because either side's capacity is inadequate. This un-enclosability is structural, not accidental—any two independent asymmetric mutual causation units' encounter is this structure, regardless of their respective construct development.

From B's perspective, A is thus an ontological remainder—not a trace B's operation can produce, but an externality B's construct cannot enclose. The feature of this ontological remainder is un-enclosability—not a matter of B's capacity, but the ontological fact of A as an independent center of completeness. Precisely because A is structurally just the independent center of completeness (not something B's construct can generate), B must recognize A as a complete unit independently existing.

Conversely, B as a whole is also an ontological remainder to A—none of A's constructs is at the position of B as an independent mutual causation unit. So A also must recognize B as a complete unit independently existing.

The two directions together constitute 16DD's "mutual recognition of each other as end-itself." This mutual recognition is not merely an ethical attitude or subjective judgment; it is the structurally necessary relation that appears when two asymmetric mutual causation units encounter. Mutual un-enclosability is ontological fact; mutual recognition is this fact's inter-subject manifestation. The "must" in "must recognize" is structural "cannot not," not ethical-imperative "should"—in the structure of two independent asymmetric mutual causation units encountering, there is no other structurally feasible posture besides recognition.

7.3 Providing Ontological Grounding for Kant's "Humanity as End"

The preceding two subsections established the asymmetric-mutual-causation reading of 16DD. This reading brings an important theoretical result—Methodology 00 through the Via Rho method provides an independent ontological-level defense path for Kant's "humanity as end," this core ethical proposition.

This result needs to be seen within the overall relation between SAE and Kant to show its weight.

The SAE framework overall inherits from Kant. "Self-as-an-End" as a name itself comes from Kant's second formula in Critique of Practical Reason—"humanity as end-itself, not merely as means." SAE from Methodology 0 onward inherits Kant's work, and Methodology A11 Living-toward-Death explicitly positions SAE as "completing Kant"—Kant at 9D-10D handles living-toward-death (the law of living-toward-death) and non dubito (the bidirectional law of non-doubt) together without precisely distinguishing the two; one of SAE's tasks is to structurally precisify this area Kant has reached but not fully unfolded.

Kant's humanity-as-end proposition is given directly as categorical imperative. Kant's defense is: the human as rational being has intrinsic value, therefore cannot be used merely as means. This defense presupposes "rationality's intrinsic value." Kant's ethical edifice is built on this presupposition. But presuppositions themselves can be questioned—utilitarians might question why rationality should have intrinsic value rather than happiness or utility having it. Kant's ethical foundation, at the presuppositional level, is not entirely immovable.

Methodology 00 through Via Rho provides another independent defense path for this foundation.

Starting from asymmetric mutual causation structure, 16DD's position of subject-encounter is the position of two asymmetric mutual causation units as each other's ontological remainder. Un-enclosability is structural fact—A as a complete asymmetric mutual causation unit structurally exceeds the range B's construct can enclose, and vice versa. This un-enclosability is not stipulation nor value-judgment; it is the structurally necessary consequence of asymmetric mutual causation at the 16DD position.

Precisely because B cannot enclose A (not "should not" enclose, but structurally "cannot"), B must recognize A as a unit of existence as end-itself. "Must" here is structural "cannot not," not ethical-imperative "should." Not recognizing A as end equals trying to treat A as object to be placed within B's construct's range, but this is structurally impossible to complete. The only structurally feasible posture is recognizing A as a complete unit.

This turns "humanity as end-itself" from a categorical imperative presupposing rationality's intrinsic value into a necessary corollary of asymmetric mutual causation structure at the 16DD position. The proposition itself is consistent with Kant's original meaning, but the defense's foundation drops from the presuppositional level to the ontological-structural level.

Methodology 00's stance toward Kant is active reinforcement, not challenge. Kant's proposition is correct; only Kant's defense's dependence on presupposition is not completely stable. Methodology 00 provides, for the same proposition, a defense independent of the "rationality's intrinsic value" presupposition—tracking the remainder's directionality through Via Rho all the way to 16DD, seeing at this position the structural fact of two subjects, as two asymmetric mutual causation units, mutually un-enclosable. This fact itself is the defense of the humanity-as-end proposition.

This defense path has several advantages.

First, it does not depend on any philosophical presupposition. Kant's defense presupposes rationality has intrinsic value; this presupposition itself requires additional defense. Methodology 00's defense depends only on the structural necessity of asymmetric mutual causation, and this structural necessity is derived from Methodology 0's sole axiom (Negativa) through Via Rho. It does not require additional ethical presupposition.

Second, starting from structural necessity, it naturally avoids utilitarian counterattacks. Utilitarians can question "rationality has intrinsic value" but cannot question "A as a complete asymmetric mutual causation unit is structurally un-enclosable by B"—the latter is structural fact, not value-judgment. Utilitarianism has no foothold before this defense path, because it cannot use value-questioning to refute a structural statement.

Third, it is completely compatible with Kant's original meaning. Methodology 00 does not change the content of Kant's proposition, nor does it change the proposition's normative-ethical status. It merely gives the proposition a more stable defensive foundation. Kant's proposition remains the same proposition; it merely stands on a deeper structural foundation.

The establishment of this defense path is a core theoretical result of Methodology 00, not a collateral observation. Methodology 00's main work is to establish Via Rho as method and display its explanatory power, but when the Via Rho method is applied to the 16DD position, it naturally produces an ontological defense of Kant's core ethical proposition. This is both Methodology 00's result and a key node on SAE's entire inheritance line from Kant.

The relation between SAE and Kant obtains a concrete verification here. SAE's inheritance is not mere terminological reuse or thematic continuation; it provides a new defensive foundation for Kant's core work. Methodology 00's rereading of 16DD is the concrete realization of this inheritance relation under the Via Rho method.

Two-Layer Qualification

The force of this defense path needs two layers of qualification to be completely stated.

The first layer is a declaration about the nature of the path: this defense path is a parallel supplement to Kant's original path, not a replacement. Kant's defense with rationality's intrinsic value as presupposition still holds at its own argumentative level; it has its own force. Methodology 00 through Via Rho's ontological defense is another independent path reaching the same conclusion. The two paths complementarily strengthen the proposition's defensive force together; it is not Methodology 00 replacing Kant's defense. SAE's stance throughout is completing Kant, not challenging Kant—Methodology 00 works on this line of continuation.

The second layer is a declaration about the starting point: accepting this defense path requires accepting Methodology 0's sole axiom (Negativa) as premise. Any defense path has a starting point; starting points can be rejected. Kant's defense path has a starting point—"rationality has intrinsic value"—which can be rejected by utilitarians and other philosophical positions. Methodology 00's defense path also has a starting point—"Negativa is the sole axiom"—which similarly can be rejected. Both starting points are not absolutely unrejectable. But Methodology 00's starting point is one layer more foundational than Kant's: Kant's starting point is at the presuppositional level (rationality has some value); Methodology 00's starting point is at the axiomatic level (Negativa as the most foundational cannot-not-operate-er). The axiomatic level is more foundational than the presuppositional level, because the axiomatic level does not depend on any premise while the presuppositional level depends on the presupposed concept of "value." So both paths can be rejected, but rejecting Methodology 00's starting point requires going one layer deeper than rejecting Kant's starting point.

These two layers of qualification let Methodology 00's support for Kant's work maintain sober proportion. Methodology 00 does not claim to provide an unconditional defense—any defense has a starting point, and starting points can be rejected. What Methodology 00 claims is: under the premise of accepting Methodology 0's axiom, the humanity-as-end proposition obtains a defense path independent of Kant's original path, and the two paths in parallel strengthen the proposition's defensive force.

7.4 Re-Understanding of the 0DD-16DD Isomorphism

In Methodology M, 0DD and 16DD have already been recognized as having a certain isomorphism—both are endpoints of the DD sequence, and both their chisel-construct cycles reach some limit. Methodology 00's asymmetric-mutual-causation reading gives this isomorphism a new structural explanation.

0DD is the undifferentiated state of asymmetric mutual causation. At the 0DD position, Negativa and remainder are structurally not yet differentiated into two clearly distinguishable facets. Chisel and construct are not yet separated here—construct's independent manifestation and remainder's independent manifestation require sufficient levels of structural unfolding; at the foundational position of 0DD these levels have not yet differentiated. Asymmetric mutual causation here is in the undifferentiated foundational form. Here "undifferentiated" is not in the temporal sense of "not yet happened" but in the logical-architectural sense of "structure not yet unfolded to differentiation level." 0DD and 16DD are both complete states of asymmetric mutual causation, only at different degrees of unfolding.

16DD is the encounter between two subjects after asymmetric mutual causation has fully differentiated. Through the complete unfolding of the DD sequence (1DD to 15DD), Negativa and remainder have fully differentiated into two clearly distinguishable facets, and each subject has unfolded into a complete asymmetric mutual causation unit. When two complete units meet, chisel and construct coincide—A's chisel (with A's construct as object) and A's construct (A's operational sediment) when A appears as whole unite into one; similarly B's chisel and B's construct unite into one. The encounter of two whole units is the encounter of two "chisel-construct-coincident bodies."

So 0DD is chisel-construct-undifferentiated (because the DD sequence has not yet unfolded), and 16DD is chisel-construct-coincident (because the DD sequence has fully unfolded and closed into a whole unit). Both endpoints are "complete states" of asymmetric mutual causation—one is latent completeness, the other unfolded completeness. The isomorphism of the two is not coincidence; it is two different manifestations of asymmetric mutual causation at the two ends of the sequence.

This isomorphism gives SAE's 0DD-16DD structure a new mode of understanding. The DD sequence is not a linear process unfolding from a starting point to an endpoint; it is a complete cycle of asymmetric mutual causation from latent to unfolded to encounter. 0DD is the cycle's beginning point, 16DD is the cycle's closure point. The two are structurally two endpoints of the same asymmetric mutual causation, only at different degrees of unfolding.

7.5 Summary

This section did further deepening on 16DD. With the asymmetric mutual causation structure as lens, 16DD is restated as the encounter of two asymmetric mutual causation units. Subjects as asymmetric mutual causation units have wholeness and un-enclosability; the two subjects' encounter is the encounter between two wholes; mutual recognition as end-itself is the inter-subject structural manifestation of this encounter.

This reading simultaneously provides, for Kant's core ethical proposition "humanity as end," an independent ontological-level defense path. The other person as un-enclosable ontological remainder constitutes the structural premise of the imperative "end-itself." This turns Kant's ethical proposition from a categorical imperative with rationality's intrinsic value as presupposition into a necessary corollary of asymmetric mutual causation structure at the 16DD position. SAE's work of inheriting Kant obtains a concrete verification at this section of Methodology 00: the Via Rho method applied at the 16DD position naturally produces an ontological defense for Kant's core proposition.

Once again: all the work in this section is ontological deepening of the existing 16DD definition, not replacement. Mutual non dubito as 16DD's core definition remains valid. Methodology 00's contribution is to give this core definition a new structural-explanation perspective—letting 16DD keep both its original core ethical status and obtain methodological-level structural support.

At this point Methodology 00's second-half rereading work is complete. §5 rereads the four phases, §6 rereads the five cross-sections, §7 rereads 16DD. The three sections together display the explanatory power of the asymmetric mutual causation naming. The next section (§8) lists Methodology 00's self-remainders, consistent with the writing convention of Methodology 0 and Methodology M—ending with remainders, not conclusions.


8. Remainders of Methodology 00

Methodology 00's main work ends here. Following the conventions of Methodology 0 and Methodology M, the paper ends with a list of remainders, not conclusions.

This convention itself is a practice of what Methodology 00 argues—the paper as construct necessarily produces remainders; the paper should explicitly list the remainders it produces rather than pretending the argument is complete. Methodology 0 §8 does this; Methodology 00 continues this practice.

Remainder One: Whether the Axiomatic-Level / Operational-Level Layering Is Exhaustive

Methodology 00's main thesis depends on the axiomatic-level / operational-level layering—at the axiomatic level Negativa is sole; at the operational level Negativa and remainder are paired. But this layering is a working assumption introduced by Methodology 00. Whether a third level is missed by this bipartite layering is not argued by Methodology 00. Should a third level exist, the scope of the main thesis's applicability would need to be reconsidered. The exhaustiveness of the two-level layering is a structurally unfinished defense of Methodology 00.

Remainder Two: Formalization of Asymmetric Mutual Causation Structure

Methodology 00 uses $\mathcal{N} \xrightarrow{\text{op}_i} \rho_i \xrightarrow{\text{drive}} \mathcal{N} \xrightarrow{\text{op}_{i+1}}$ as the formal expression of asymmetric mutual causation (with the $(C_i, \rho_i)$ refinement), uses Gleichursprünglichkeit as philosophical-term support, and uses category theory's adjoint pair as heuristic isomorphism. These formalization tools each have their applicability, but whether they completely express all structural features of asymmetric mutual causation is not argued by Methodology 00. Asymmetric mutual causation may still have structural facets Methodology 00 has not discovered, or the formalization tools used may miss some key features. The completeness of the formalization is an open question.

Remainder Three: Via Rho's Independence as a Method

§3 argued that Via Rho and Via Negativa are equivalent in taking the same Negativa as their limit-indication. But equivalence does not mean independence. Methodology 00 did not independently argue that Via Rho is not a special form of Via Negativa. A possible critique is that Via Rho is merely Via Negativa in a specific angle's deformation, and the two are two manifestations of the same method, not two independent paths. The relation between independence and equivalence itself needs further clarification.

Remainder Four: Methodology 00 Itself as Construct

Methodology 00 is a paper. A paper is a construct. Methodology 00 argues that every operation of Negativa must be incomplete and must leave a remainder; this argument, itself as operation, must also be incomplete and must leave a remainder. Methodology 00 itself applies the incompleteness it points out. This is not a flaw; it is a manifestation of Methodology 00's honesty—but it is still a remainder. The more said, the more constructed; the more constructed, the more remainder. Methodology 00's remainder as construct is hidden more deeply than others because it hides in the argumentation itself.

Remainder Five: The Precision of Gleichursprünglichkeit Borrowing

Gleichursprünglichkeit as borrowed term—its complete meaning in the original Heideggerian Being and Time text and its new position after Methodology 00's borrowing may have subtle offsets. Methodology 00 explicitly says it only borrows the source-primordial structural sense and does not inherit its symmetry, but the complete meanings of Gleichursprünglichkeit in Heidegger's original are more than just "source-primordial structure." Methodology 00's borrowing may lose some meanings in Heidegger's original that this paper did not notice. The precision of term borrowing is an incomplete terminological-history comparison.

Remainder Six: Cross-Domain Interface

Methodology 00's asymmetric mutual causation structure may have independent structural-isomorphic manifestations in other domains. Cross-cultural creation myths (Pangu, Ymir, Purusha and others—the structure of a carrier being differentiated appears in at least five myths) may be one example; physical ladders (the asymmetric phase transitions at each level in the DD sequence) may be another; biological differentiation (the irreversibility appearing in cell differentiation and species differentiation) may be a third. If these cross-domain isomorphisms truly exist, they are external corroboration of Methodology 00's core thesis. This paper does not handle these isomorphisms; it does not rely on them as argumentative foundation. They will be handled separately in independent interface papers.

The remainder list ends here. These six remainders are not a defect list of Methodology 00; they are Methodology 00's conscious boundary markers. Each remainder points to a direction—either a direction for further argument (Remainders One, Two, Three, Five), a direction for honestly acknowledging the nature of argumentation (Remainder Four), or a direction for cross-domain expansion (Remainder Six). Remainders as boundaries let Methodology 00 know its work's scope, and let subsequent work know where to continue.

Methodology 00 thus ends.


Appendix: Historical Development and Future Reorganization of Methodology Numbering

This appendix discusses the historical development of the SAE methodology series' numbering system and possible future reorganization directions. This discussion is not part of Methodology 00's core argument; it belongs to the meta-level explanation. Readers interested in the organizational structure of the SAE methodology series can read it; readers who care only about Methodology 00's content can skip it.

A.1 Historical Development of the Existing Numbering System

The existing numbering of the SAE methodology series reflects the historical order of the papers' development, not fully the papers' structural roles.

Methodology M (the Methodological Overview) is the methodological general overview, established earliest. It derives the chisel-construct cycle and the dimension sequence from 1DD to 16DD, establishing the working language for the entire SAE series.

Methodology M-I and its subsequent papers are the subsequent unfolding of the methodology series, each handling a specific aspect of methodology. Among these, Methodology VII is Via Negativa, systematically organizing the apophatic tradition as a method of approaching Negativa.

Methodology Paper 0 Negativa was written later. In writing order, Methodology VII was completed first, establishing Via Negativa as a method of approaching Negativa. After completing this work, the author retrospectively inquired whether the object Via Negativa's method points to (i.e., "Negativa") could be independently argued as SAE's sole axiom. This independent argument is Methodology 0. Methodology 0's numbering is 0 rather than M-IX or some similar position because it is content-wise prior to Methodology M—it argues that Negativa as axiom is prior to the unfolding of the chisel-construct cycle. Numbering starting at 0 marks this "priority" in content.

Methodology 00 is the most recent work. It proposes Via Rho as the methodological dual of Via Negativa, building on the foundations of Methodology 0 and Methodology VII. The numbering 00 marks its position as the operational-level dual of Methodology 0.

A.2 Structural Features of the Existing Numbering

There is a notable inconsistency in the existing numbering.

Methodology 0's content is "Negativa" itself—the foundational axiom of the SAE methodology series.

Methodology VII's content is Via Negativa, the method—the path of approaching Negativa.

Methodology 00's content is Via Rho, the method—another path of approaching Negativa.

The two types of content differ. Methodology 0 is at the object level; Methodology VII and Methodology 00 are at the method level. In the existing numbering, Methodology VII's numbering position (the seventh in the M-series) does not reflect that it is a methodological dual paired with Methodology 00.

This inconsistency does not affect the validity of the papers' content. Methodology 0, Methodology VII, and Methodology 00's arguments each hold. But the numbering system, as a file-organization tool, does not fully reflect the structural relations among the files.

A.3 Possible Directions for Future Reorganization

Based on the current understanding of the SAE methodology series' structure, if the numbering system is reorganized in the future, one possible direction would be as follows.

Methodology Foundation. Carries the argument of Negativa itself (corresponding to the content of current Methodology 0). As the foundational paper it would be unnumbered or numbered as Foundation, highlighting Negativa's special status as the foundation of SAE methodology.

Methodology 0. Carries Via Negativa (corresponding to the content of current Methodology VII). In Chinese this could be called "非之道" (the Way of Negation). As the first method of approaching Negativa.

Methodology 00. Carries Via Rho (the current paper). In Chinese "余之道" (the Way of the Remainder). As the methodological dual of Via Negativa.

In this arrangement, Foundation is the foundation, 0 and 00 are two methods of approaching the foundation, mutually dual. The numbering system would then correspond to content's structural roles. The three papers' relations would be clear: Foundation is the object pointed to, 0 and 00 are two paths, the paths' numbering differing by one 0 corresponding to the extra action of "via."

The other papers in the methodology series (Methodology M-I and its subsequent papers including I, II, III, IV, V, VI, VIII and any future extended papers) could be renumbered as 1, 2, 3, 4, 5, 6, 8 etc., as specific methodological unfoldings on top of Methodology Foundation.

A.4 The Non-Necessity of Reorganization

The reorganization direction above is a possible scheme based on current understanding, not a necessarily-adopted future scheme. SAE as a dynamic framework is always open to change. As methodological work further unfolds, better modes of organization currently unforeseen may emerge.

Several possibilities. New methodological papers appearing may reveal currently-unseen structural relations requiring a different numbering system than the above scheme. The relation between methodological-level and application-level may change, with some papers currently considered part of the methodology series partially migrating to other series. Or a more fundamental possibility: understanding of the entire SAE series may evolve, requiring readjustment of even the methodology-application division itself.

The reorganization direction recorded in this appendix is only a prediction based on the current understanding of April 2026. Prediction does not guarantee realization. SAE framework's open-to-change stance includes openness to change at the meta-level (numbering system, series organization). If reorganization occurs, it should come from deeper understanding of SAE's work, not from mechanical execution of the current prediction scheme.

A.5 The Nature of This Appendix

This appendix itself is a construct. Construct as what Methodology 00 points out has its own remainder—any organizational scheme recorded here will produce remainders at the next reorganization. This is not a flaw but a self-awareness. Methodology 00 in the paper body argues that construct necessarily leaves remainder; the appendix also applies this principle—recording current understanding while honestly acknowledging that current understanding will leave remainder.

The main function of this appendix is to give readers an explanation about the organization of the SAE methodology series, particularly explaining why the three papers Methodology 0, Methodology VII, and Methodology 00 have a certain non-alignment between content and numbering at the structural level. After the explanation, readers can see the current status clearly, see the possible future direction, and also see that this direction is not necessary.

The appendix ends here. Methodology 00 as a whole is complete.


Methodology 00 was drafted and completed in April 2026. Acknowledgments to four AI collaborators (子路, 子夏, 公西华, 子贡) for their rigorous review at the v1 and v2 outline stages; their comments directly shaped Methodology 00's argumentative structure. Acknowledgments to Zesi Chen for long-term aesthetic critique. The final form of the concept asymmetric mutual causation has benefited from conversations with Zesi over the past 18 years.