Self-as-an-End
Self-as-an-End Theory Series · Applied — Philosophy

Reason Cannot Not: An SAE Refinement of Kant’s Four Formulations of the Categorical Imperative
理性不得不:SAE对康德四定言律令的句式精细化

Han Qin (秦汉)  ·  Independent Researcher  ·  2026
DOI: 10.5281/zenodo.19751513  ·  Full PDF on Zenodo  ·  CC BY 4.0
Abstract

This paper offers a sentence-form-theoretic refinement (*satzformentheoretische Verfeinerung*) of Kant's four formulations of the categorical imperative — the formula of universal law, the formula of humanity as end in itself, the formula of autonomy, and the formula of the kingdom of ends — within the SAE 15DD-16DD coordinate. It rewrites Kant's four "ought"-modal formulas as four "cannot not" 15DD-16DD ontological statements, establishing SAE ethics as a refinement (*Verfeinerung*) of Kantian ethics at the sentence-form layer. The paper takes its starting point from *Metaphysics of Self-as-an-End: Dimensional Sentence-Form Theory* (metaphysics-satz, DOI 10.5281/zenodo.18894567), which provided a compressed diagnosis of Kant's four formulations in §VI Ray 1 — that all four use the 14DD imperative structure "Handle so, daß…" to carry 15DD-16DD content, yielding the overlap of error-type II (instrumentalization) and error-type IV (alterity erasure). The present paper expands this compressed diagnosis into a complete account: each of the four formulations carries three specific 14DD residues (twelve in total), plus four shared sentence-form features common to all four (ought-modal, subject-object separation, hypothetical-or-counterfactual position, mediating faculty). The refinement gives: I. Reason cannot not reason (corresponding to Kant's first formulation: universalization / form); II. Reason cannot not develop (as the concrete operating mode of autonomy as background); III. Reason cannot not have direction, that is, purpose (corresponding to Kant's second formulation: humanity as end / matter); IV. Reason cannot not be interrogated (corresponding to Kant's fourth formulation: kingdom of ends / system; standing in an *engine-produces* relation to 16DD cooperative imperative). Autonomy (Kant's third formulation) is not listed as a fifth clause but instead serves as the *common background* (*Hintergrund*) running through all four — preserving the core position of Kant's autonomy principle while elevating it from "side-by-side third" to "permeating four." This treatment liberates autonomy from Kant's restriction to the will (*Wille*) as a specific faculty, expanding it into the operating mode of the 15DD subject across all dimensions (cognition, faith, imperative, cooperation). The paper places existing SAE works within this refined coordinate: A16 *One's Own Law* (DOI 10.5281/zenodo.19037566) as the complete unfolding of clause III; *Kategorischer Glaube* (DOI 10.5281/zenodo.19719083) as the manifestation of autonomy-as-background on the inward-facing side of 15DD. Together, A16 and *Kategorischer Glaube* constitute the outward-inward duality of autonomy at 15DD. A complete elaboration of clause IV (the 16DD cooperative imperative as a standalone treatise) is identified as the next position in SAE ethics, not addressed in the present paper. SAE is not founded outside Kant; it is the continued unfolding of Kantian ethics with 21st-century tools (the dimensional sentence-form sequence, the chisel-construct cycle, the remainder ρ, the *cannot not* modal). Kant did the most precise work he could with 18th-century tools; the further refinement here depends on tools that did not yet exist in his time. Keywords: categorical imperative; *Reason cannot not*; *Vernunft kann nicht nicht*; *Kategorischer Imperativ*; four formulations refinement; formula of universal law; formula of humanity as end; formula of autonomy; formula of kingdom of ends; SAE refinement of Kant; 15DD-16DD sentence-form theory; 14DD residue diagnosis; metaphysics-satz; *Verfeinerung* ---

Keywords: categorical imperative, Kant, sentence-form refinement, 15DD-16DD, cannot not, SAE ethics, four formulations, Verfeinerung

Die Vernunft kann nicht nicht: Eine SAE-Verfeinerung von Kants vier Formeln des kategorischen Imperativs

理性不得不:SAE对康德四定言律令的句式精细化

Han Qin (秦汉) · Independent Researcher · 2026

DOI: 10.5281/zenodo.19751513


Abstract

This paper offers a sentence-form-theoretic refinement (satzformentheoretische Verfeinerung) of Kant's four formulations of the categorical imperative — the formula of universal law, the formula of humanity as end in itself, the formula of autonomy, and the formula of the kingdom of ends — within the SAE 15DD-16DD coordinate. It rewrites Kant's four "ought"-modal formulas as four "cannot not" 15DD-16DD ontological statements, establishing SAE ethics as a refinement (Verfeinerung) of Kantian ethics at the sentence-form layer.

The paper takes its starting point from Metaphysics of Self-as-an-End: Dimensional Sentence-Form Theory (metaphysics-satz, DOI 10.5281/zenodo.18894567), which provided a compressed diagnosis of Kant's four formulations in §VI Ray 1 — that all four use the 14DD imperative structure "Handle so, daß…" to carry 15DD-16DD content, yielding the overlap of error-type II (instrumentalization) and error-type IV (alterity erasure). The present paper expands this compressed diagnosis into a complete account: each of the four formulations carries three specific 14DD residues (twelve in total), plus four shared sentence-form features common to all four (ought-modal, subject-object separation, hypothetical-or-counterfactual position, mediating faculty).

The refinement gives:

I. Reason cannot not reason (corresponding to Kant's first formulation: universalization / form);

II. Reason cannot not develop (as the concrete operating mode of autonomy as background);

III. Reason cannot not have direction, that is, purpose (corresponding to Kant's second formulation: humanity as end / matter);

IV. Reason cannot not be interrogated (corresponding to Kant's fourth formulation: kingdom of ends / system; standing in an engine-produces relation to 16DD cooperative imperative).

Autonomy (Kant's third formulation) is not listed as a fifth clause but instead serves as the common background (Hintergrund) running through all four — preserving the core position of Kant's autonomy principle while elevating it from "side-by-side third" to "permeating four." This treatment liberates autonomy from Kant's restriction to the will (Wille) as a specific faculty, expanding it into the operating mode of the 15DD subject across all dimensions (cognition, faith, imperative, cooperation).

The paper places existing SAE works within this refined coordinate: A16 One's Own Law (DOI 10.5281/zenodo.19037566) as the complete unfolding of clause III; Kategorischer Glaube (DOI 10.5281/zenodo.19719083) as the manifestation of autonomy-as-background on the inward-facing side of 15DD. Together, A16 and Kategorischer Glaube constitute the outward-inward duality of autonomy at 15DD. A complete elaboration of clause IV (the 16DD cooperative imperative as a standalone treatise) is identified as the next position in SAE ethics, not addressed in the present paper.

SAE is not founded outside Kant; it is the continued unfolding of Kantian ethics with 21st-century tools (the dimensional sentence-form sequence, the chisel-construct cycle, the remainder ρ, the cannot not modal). Kant did the most precise work he could with 18th-century tools; the further refinement here depends on tools that did not yet exist in his time.

Keywords: categorical imperative; Reason cannot not; Vernunft kann nicht nicht; Kategorischer Imperativ; four formulations refinement; formula of universal law; formula of humanity as end; formula of autonomy; formula of kingdom of ends; SAE refinement of Kant; 15DD-16DD sentence-form theory; 14DD residue diagnosis; metaphysics-satz; Verfeinerung


Terminology

SAE term German English Sentence-form / Kant correspondence
理性不得不理性 Die Vernunft kann nicht nicht vernünfteln Reason cannot not reason First formulation (universalization / form)
理性不得不发展 Die Vernunft kann nicht nicht sich entwickeln Reason cannot not develop Concrete operating mode of autonomy-as-background
理性不得不有方向,即目的 Die Vernunft kann nicht nicht eine Richtung haben, d.h. einen Zweck Reason cannot not have direction, that is, purpose Second formulation (humanity as end / matter)
理性不得不被追问 Die Vernunft kann nicht nicht befragt werden Reason cannot not be interrogated Fourth formulation (kingdom of ends / system)
自律作为底色 Autonomie als Hintergrund Autonomy as background Third formulation (autonomy / source): position re-distribution from "parallel third clause" to "running through all four"

A note on vernünfteln: this verb has, both in Kant's own usage and in the broader philosophical tradition, the neutral sense of "exercising reason" or "carrying out rational thought." In ordinary German it sometimes carries a slightly pejorative connotation (referring to petty rationalization). The present paper uses the term in its philosophical-tradition neutral sense — equivalent to Vernunft vollziehen (carrying out reason) — paralleling the Chinese "理性不得不理性" and English Reason cannot not reason in their use of the noun-as-verb structure: the subject's rationality persistently operates itself as rational.


I. Kant's Four Formulations: Four Faces of One Categorical Imperative

I.1. Kant's Own Account of the Relation Among the Four Formulations

In Grundlegung zur Metaphysik der Sitten, Kant gives multiple formulations of the categorical imperative. Philosophical tradition typically distills these into four (or three plus a corollary), each expressing the same imperative from a different angle.

First formulation: formula of universal law (Formel des allgemeinen Gesetzes)

> Handle nur nach derjenigen Maxime, durch die du zugleich wollen kannst, dass sie ein allgemeines Gesetz werde.

>

> Act only according to that maxim by which you can at the same time will that it become a universal law.

This formulation views the categorical imperative from the side of form — the formal condition for a maxim to qualify as a moral law: it must be universalizable, that is, capable of being thought as a universal law without self-contradiction or volitional impossibility. This is a purely formal test on maxims.

Second formulation: formula of humanity as end in itself (Formel der Zweckmäßigkeit)

> Handle so, dass du die Menschheit sowohl in deiner Person als in der Person eines jeden anderen jederzeit zugleich als Zweck, niemals bloß als Mittel brauchst.

>

> Act in such a way that you treat humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means.

This formulation views the categorical imperative from the side of matter — what content the imperative constrains. The content is not a list of specific actions but a regulation concerning the object toward which action is directed: it must be directed toward persons (rational beings) as ends in themselves. Note the word bloß (merely) — Kant does not prohibit instrumental use; he prohibits treating persons merely as means, erasing their dimension as ends in themselves.

Third formulation: formula of autonomy (Formel der Autonomie)

> Handle so, dass der Wille durch seine Maxime sich selbst zugleich als allgemein gesetzgebend betrachten könne.

>

> Act in such a way that the will can through its maxim regard itself at the same time as universally legislating.

This formulation views the categorical imperative from the side of source — where the imperative comes from. The answer: from the rational subject itself. The rational subject is both legislator and subject; this identity of legislating and being-subject-to constitutes autonomy (Autonomie). This stands opposed to heteronomy (Heteronomie, receiving law from outside). Kant's central ethical thesis — that human dignity rests on autonomy — is concentrated in this formulation.

Fourth formulation: formula of the kingdom of ends (Formel des Reichs der Zwecke)

> Handle so, als ob deine Maxime durch deinen Willen zum allgemeinen Naturgesetze werden sollte.

>

> Act in such a way that your maxim could always be regarded as a maxim of universal legislation belonging to the kingdom of ends (das Reich der Zwecke).

This formulation views the categorical imperative from the side of system — what kind of community emerges when all rational subjects act autonomously and treat one another as ends. The answer: the kingdom of ends — a community in which all rational subjects mutually recognize one another as legislators and ends in themselves. This is the systemic figure that emerges when the first three formulations operate together at their limit.

Kant himself states explicitly in Grundlegung that the four formulations express the same categorical imperative from different angles — a maxim that can be universalized (first) must respect all rational subjects as ends in themselves (second); the source of such universalization can only be the autonomous self-legislation of rational subjects (third); all such autonomous legislators together constitute the kingdom of ends (fourth). The four formulations are not four parallel imperatives but the same imperative unfolded in four perspectives.

I.2. The Task of This Paper

The task of this paper is not to challenge Kant's structural claim but to refine it at the SAE 15DD-16DD sentence-form level. The problem is not Kant's content — the content itself is accurate at 15DD-16DD (the rational self-consistency of the first formulation, the humanity-as-end of the second formulation in 15DD, the autonomy principle of the third formulation running through 15DD-16DD, and the kingdom of ends of the fourth formulation in 16DD). The problem is Kant's sentence-form. The content of the four formulations distributes across 15DD and 16DD, but their sentence-form remains uniformly stuck at the 14DD imperative structure.

SAE has performed sentence-form diagnoses on Kantian concepts in earlier papers (cf. A16 One's Own Law, DOI 10.5281/zenodo.19037566; Kategorischer Glaube, DOI 10.5281/zenodo.19719083, §I, on Vernunftglaube). The finding there: Kant's Du sollst (you ought) modal is a 14DD sentence-form (the imperative/hypothetical structure of the purpose-anchoring layer), not a 15DD sentence-form (the cannot not of the ontological layer). The same content under different sentence-forms carries entirely different semantic weight. "You ought to treat the other as an end" (14DD) and "the other's noumenal presence leaves me with no option of not doing B" (15DD) are the same content expressed at two different sentence-form layers.

The present paper extends this work to all four of Kant's formulations. Each formulation has 15DD-or-16DD content paired with 14DD sentence-form. The task is to redo the four formulations at the 15DD-16DD sentence-form layer, matching sentence-form to content. This is the satzformentheoretische Verfeinerung (sentence-form-theoretic refinement) that SAE performs upon Kant's categorical imperative.

I.3. The Position of This Paper Within the SAE Series

The starting point of this paper is Metaphysics of Self-as-an-End: Dimensional Sentence-Form Theory (metaphysics-satz, DOI 10.5281/zenodo.18894567). That paper established the dimensional-sentence-form isomorphism (0DD-16DD) as SAE's foundational coordinate, and in §VI Ray 1 (Kant's Imperatives) gave a first compressed sentence-form diagnosis of Kant's four formulations:

> Kant's three formulations all use the sentence-form Handle so, daß… — the imperative structure of the purpose-hypothetical imperative. The second formulation attempts to express the absolute imperative (15DD) in content; the third formulation attempts to express the cooperative imperative (16DD) in content. But both use 14DD sentence-form. This constitutes the overlap of error-type II (instrumentalization) and error-type IV (alterity erasure): he wrote cannot not as ought, and wrote bilateral-subject structure as unilateral-subject command. Kant saw what was right — humans are ends, not merely means. But the only tools he had for writing it down were 14DD sentence-forms. The pearl was at 15DD-16DD; the casket was at 14DD.

The diagnosis in metaphysics-satz is a compressed version — it identifies that Kant uses 14DD sentence-form to carry 15DD-16DD content, but does not unfold the specific residues of each individual formulation. The task of the present paper is to expand this compressed diagnosis into a complete account: what specific 14DD residues each of the four formulations carries, and what the corresponding SAE 15DD-16DD sentence-form should look like.

The metaphysics-satz correspondence between Kant's formulations and SAE layers:

  • Second formulation (humanity as end) → absolute imperative (15DD): the other's purpose is A, so I cannot not do B
  • Third formulation (autonomy) and fourth formulation (kingdom of ends) → cooperative imperative (16DD): I for purpose A, the other for purpose B, we cannot not do C

The first formulation (universalization) was not assigned to a specific SAE layer in metaphysics-satz. The present paper argues: the substance of the first formulation is reason's requirement of self-consistency. It does not correspond to any specific layer's content imperative but rather to the operating condition that runs through 15DD-16DD as a whole — reason, in operating as reason, must maintain self-consistency. This is the structural position of clause I "Reason cannot not reason" to be unfolded in §III.

The relation between the present paper and the metaphysics-satz compressed diagnosis must be made explicit, lest readers, encountering §III.2 (clause II as the operating mode of autonomy-as-background) and §IV (autonomy as the background running through all four), experience tension regarding "where does the third formulation actually go?"

The present paper does not overturn the metaphysics-satz compressed diagnosis; it redistributes the diagnostic results at higher resolution. The metaphysics-satz judgment that "the content of the third formulation belongs to 16DD" is accurate at the compressed level — the content of the third formulation (reason as autonomous legislator) does indeed point toward the multi-subject cooperative structure. But at higher resolution, the third formulation contains two components: autonomy-as-principle itself (reason gives itself law — this is the background running through all dimensions) plus the multi-subject realization of autonomy (the cooperative structure in which all autonomous legislators mutually legislate and recognize — this belongs to the fourth formulation, the kingdom of ends, and its 16DD realization in the cooperative imperative). The compressed diagnosis assigned both together to the third formulation; the present paper, at higher resolution, separates them — autonomy-as-principle becomes the background traversing all four clauses (§IV), the cooperative imperative becomes the produce of the fourth formulation in clause IV's engine role (§V.3). After this separation, the content of the third formulation does not disappear but is distributed in a more precise form: as background-form running through all clauses (§IV) and as specific content realized in the fourth formulation's 16DD form (§V.3).

This redistribution makes the paper's overall structure tighter: the compressed diagnosis answers "which Kantian content belongs to which SAE layer"; the present paper answers "in what form (background, clause, engine, produce) each Kantian content distributes within the SAE coordinate." The first kind of precision is layer assignment; the second kind is structural position. The latter is stricter than the former, and provides the latter with independent structural support.

Within this diagnostic framework, several existing SAE papers handle different parts of Kant's four formulations:

  • A16 One's Own Law (DOI 10.5281/zenodo.19037566) — the 15DD sentence-form refinement of the second formulation (humanity as end). The absolute imperative as "the other's purpose is A, so I cannot not do B" — moving Kant's "you ought to treat the human as an end" from 14DD to 15DD sentence-form.
  • Kategorischer Glaube (DOI 10.5281/zenodo.19719083) — the unfolding of the autonomy principle on the inward-facing side of 15DD. Categorical faith as the subject's non-externalizable bearing of its own standing, manifesting autonomy in the dimension of faith (rather than the dimension of will). The paper notes that categorical faith's "autonomy" is more foundational than Kant's volitional autonomy — it is the operating mode by which the subject stands as subject at all.
  • The 16DD cooperative imperative (defined complete in metaphysics-satz: I for purpose A, the other for purpose B, we cannot not do C) — the 15DD-16DD realization of the third formulation (autonomy in plural form) and the fourth formulation (kingdom of ends). C does not belong to A nor to B; it is the action forced into being by the meeting of two independent purposes — the non-idealized concrete structure of Kant's kingdom of ends.

But to date, SAE has not done one piece of work: placing Kant's four formulations as a unified whole within the SAE sentence-form coordinate, performing a coordinated unfolded diagnosis and refinement. The metaphysics-satz initiated this work but only at compressed resolution; A16, Kategorischer Glaube, and the scattered 16DD discussions in various papers each handle one part of the four formulations. The internal relations among the four formulations — as four faces of the same categorical imperative — have not been completely re-articulated on the SAE side. The present paper fills this gap.

As an integrative declaration, the present paper does three things:

(i) Expand each of Kant's four formulations' 14DD residues into a complete account, building on metaphysics-satz's compressed diagnosis (§II).

(ii) Provide the SAE refinement of the four formulations as four "Reason cannot not" statements at the 15DD-16DD sentence-form layer (§III).

(iii) Display, within this refined structure, the specific positions occupied by existing SAE papers (A16, Kategorischer Glaube, the future 16DD treatise), making explicit their common Kantian foundation (§V); and provide an integrative declaration of SAE ethics as the 15DD-16DD sentence-form refinement of Kantian ethics (§VI).

SAE is not founded outside Kant; it is the continued unfolding of Kantian ethics under 21st-century tools (the dimensional sequence, the chisel-construct cycle, the remainder ρ, the cannot not modal). It continues Kant's methodology (establishing coordinates, distinguishing the a priori from the a posteriori, grounding in autonomy, using cannot not modal), refining the four formulations at the 15DD-16DD sentence-form layer using tools that did not yet exist in Kant's time.

II. The 14DD Residue Diagnosis of Each Formulation

Terminological note: This paper uses "14DD residue" (14DD-Rest / 14DD residue) to denote a sentence-form mismatch — when a proposition's content belongs to 15DD-16DD but its sentence-form belongs to 14DD (the purpose-anchoring layer, e.g., "ought," hypothetical, command structures), the 14DD sentence-form features become a residue upon the 15DD-16DD content. This term is etymologically aligned with SAE's core concept "remainder" (ρ, Rest); it is also used in the Kategorischer Glaube paper (DOI 10.5281/zenodo.19719083) as the same concept.

The metaphysics-satz §VI Ray 1 has already given a compressed version of the diagnosis of Kant's four formulations: all four use the 14DD imperative structure Handle so, daß…; the second formulation's content is at 15DD; the third formulation's content is at 16DD; the mismatch is the overlap of instrumentalization (error-type II) and alterity erasure (error-type IV). The present section expands this compressed diagnosis: what specific 14DD residues each of the four formulations carries, and what the corresponding SAE 15DD-16DD form should be.

The diagnosis is not a critique of Kant — Kant did the most precise work he could within the philosophical tools of the 18th century. The diagnosis serves to determine what 14DD features SAE must remove when redoing the formulations at the 15DD-16DD sentence-form layer.

II.1. The 14DD Residues of the First Formulation

The formula of universal law: "Act only according to that maxim by which you can at the same time will that it become a universal law."

Residue one: the variant of hypothetical command. "If you want your maxim to be rational, then you ought to make it universalizable" — the condition "you want your maxim to be rational" plus the ought-result "make it universalizable." This is the typical 14DD hypothetical-imperative structure (hypothetical imperative), although Kant himself classifies the formulation as categorical. Categorical in form, hypothetical at depth.

Residue two: the binary structure of maxim and law. Kant posits the distinction between Maxime (subjective principle of action) and Gesetz (objective moral law), then through the universalization test elevates maxims to laws. This binary structure is 14DD — positing one tool (maxim) and one purpose (law), aligning the tool toward the purpose. The 15DD sentence-form does not require this binary — reason's operation itself is rationalizing (vernünfteln); it does not require a process of first having a "subjective maxim" then having it tested into "objective law."

Residue three: Sollst as modal. The formulation "Du sollst..." (you ought) makes the law a command issued from outside to the subject — even when the outside is reason itself acting through autonomy. The 15DD sentence-form does not require this command structure — it is not "reason commands you to rationalize" but "reason cannot not reason"; rationalization is the way reason exists as reason, not the result of being commanded.

The SAE task: rewrite the first formulation from "if your maxim is to be rational, then it ought to be universalizable" (14DD hypothetical structure) to "Reason cannot not reason" (15DD ontological structure) — reason's mode of being as reason already includes self-consistency (the underlying core of universalization), without requiring an external "ought" to demand this consistency.

II.2. The 14DD Residues of the Second Formulation

The formula of humanity as end: "Act in such a way that you treat humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means."

Residue one: the "treat-as" sentence-form. Although this formulation speaks of humans as ends in themselves (15DD content), Kant uses the sentence-form "treat X as Y" (etwas als Y behandeln) — a subject-object-separation processing relation in which the subject "treats" the object as some characterization. The 15DD's "the other in the noumenal mode is present" is not "I treat the other as a noumenon" (which would attribute a property to the other through subjective construal); it is that the other is already in noumenal mode, and my action unfolds under the condition of this presence. The "treat-as" form implies subjective construction; the 15DD form removes this subjective construction — noumenal status is not "treated-as" but is a way of being.

Residue two: the negative qualification "never merely as a means." The principal positive content of this formulation (treat humans as ends) is paired with a negative qualifier (not merely as means). This makes the principle a complex command with an exception clause — humans may be treated as means (instrumental use is permitted), but not merely as means. The word bloß (merely) does much philosophical work, but as a qualifying clause it makes the principle structurally complex — not a pure ontological statement but a mixed structure of "do X, but do not entirely do X." A16's work shows: in the 15DD sentence-form, "the other's noumenal presence leaves me with no option of not doing B" does not require this kind of "permit but not entirely permit" qualification — the condition of subject-as-noumenon-present already determines the structure of action.

Residue three: ends as the object of treatment. Kant places "ends" in the position of the subject's moral judgment — whether to treat something as an end is the subject's moral evaluation. The 15DD position differs: the noumenon is the end, requiring no judgment. Whether one subject acknowledges another subject as a noumenon is not an empirical question of judgment but a question of 15DD-layer ontological structure — for a subject to stand as a 15DD subject already presupposes noumenal recognition of all other 15DD subjects.

The SAE task: rewrite the second formulation from "you ought to treat humans as ends" (14DD judgment form) to "Reason cannot not have direction, that is, purpose" (15DD ontological structure) — reason's operation necessarily has direction, and at the 15DD layer this direction is the noumenal presence of other subjects (the other's purpose entering my constraint). This is also the content of the absolute imperative in A16.

II.3. The 14DD Residues of the Third Formulation

The formula of autonomy: "Act in such a way that the will can through its maxim regard itself at the same time as universally legislating."

Residue one: the binary position of legislator-and-subject. Autonomy is here formulated by Kant as the structure of "the same subject simultaneously functioning as legislator and as subject-to-the-law." This structure itself preserves the legislator/subject distinction — only that the same subject occupies both positions. The 15DD sentence-form does not require this binary — reason is not "both legislating and subject"; reason is "operating itself." Operation is legislating (operation-mode is law) and is being-subject (operating in accordance with operation-mode); the three are not separable.

Residue two: the "regard-as" reflexive structure. The same subject-object-separation problem — the subject treats/regards itself as some role (legislator). This is reflexive self-relation, in which the subject makes a judgment about itself (judging itself to be a legislator). The 15DD self-relation does not require this reflexive judgment — autonomy as background is not the result of the subject judging itself, but the way reason exists as reason in operation.

Residue three: will as the agent of legislation. Kant places autonomy in the faculty of will (Wille) — the will legislates, the will is subject. But the will, as a specific psychological-rational faculty, is only one face of the 15DD subject. Confining autonomy to the will limits its scope. The 15DD autonomy does not operate only at the will level — it operates in cognition (reason cannot not have its own cognitive direction), in faith (categorical faith as non-externalizable bearing), in imperative (absolute imperative as the action that cannot not be done under the noumenal presence of the other), in cooperation (16DD's "we cannot not"). Autonomy is the existence-mode of the 15DD subject as a whole, not the property of a specific faculty.

The SAE task: rewrite the third formulation from "the will may regard itself as legislator" (14DD specific-faculty reflexive structure) to "autonomy as common background of all four clauses" (15DD subject-whole existence-mode) — autonomy is not listed as a separate clause but runs through all four clauses as their common root. All "Reason cannot not..." statements are laws given by reason to itself, not laws given to reason from outside.

II.4. The 14DD Residues of the Fourth Formulation

The formula of the kingdom of ends: "Act in such a way that your maxim could always be regarded as a maxim of universal legislation belonging to the kingdom of ends."

Residue one: "kingdom" as ideal (Idee). Kant himself acknowledges that the kingdom of ends is an idea (Idee), an ideal community that does not exist in reality. Placing the object of the fourth formulation in the position of "ideal" weakens its actual constraint on present action — "act as if you were in the ideal community" introduces, under the 14DD hypothetical structure, yet another if: if there were a kingdom of ends, then you ought to act as its member.

Residue two: the "as a member" identity assumption. Asking the subject to imagine itself as a member of the kingdom of ends and infer how a member would act. This is counterfactual identification — the subject is not actually a member of the kingdom of ends; it is pretending to be. Such imagined identity assumptions are standard in 14DD, but 15DD requires actual existential conditions — the subject is not pretending to be with others in the kingdom of ends; the subject is actually with the other in a "I for purpose A, the other for purpose B, we cannot not do C" cooperative structure.

Residue three: the kingdom of ends as idealized universalization. Kant treats the fourth formulation as the idealized result of combining the first formulation (universalization) and the second formulation (humans as ends). This combination preserves the formalization of the first formulation and the "treat-as" form of the second formulation, stacking two 14DD residues. SAE's "I for A, the other for B, we cannot not do C" is a structural statement of concrete cooperation, not an idealized imagination — two specific subjects in concrete circumstances jointly carrying a third term in structurally-cannot-not fashion. The 16DD cooperative imperative is not a variant of the fourth formulation; it is the fourth formulation realized non-idealized in 15DD-16DD concrete cooperation.

The SAE task: rewrite the fourth formulation from "your maxim may be regarded as a member's maxim of the kingdom of ends" (14DD idealized identity assumption) to "Reason cannot not be interrogated" (15DD other-arrival structure) — reason's operation necessarily faces interrogation from others (demands, questions, calibrations from other rational subjects); this interrogation at the cooperative level is the structure of "we cannot not." The kingdom of ends is not an ideal community; it is the actual structure of mutually-interrogating, mutually-calibrating rational subjects.

II.5. Common Features of the Four Formulations' 14DD Residues

The four formulations' 14DD residues share common features:

  • All use the sollst (ought) modal rather than the kann nicht nicht (cannot not) modal — command rather than ontology.
  • All employ the subject-object-separation processing relation ("treat X as Y," "regard yourself as legislator") — the subject makes judgments about objects rather than the ontological structure operating directly.
  • All operate in hypothetical or ideal positions (universalizable maxim, the human treated as end, the will as legislator, member of the kingdom of ends) — hypothetical or counterfactual rather than actual presence.
  • All depend on a mediating faculty (will, maxim, reflection) — bearing the imperative through a specific faculty rather than through the subject's whole way of being.

These common features are not Kant's lack of rigor — to the contrary, they represent the precision Kant could achieve within 18th-century philosophical tools. To remove these 14DD residues requires 21st-century tools: the chisel-construct cycle's dynamic generation mechanism, the remainder (ρ) as ontological status, primordial chaos (0D) as starting point, the 15DD-16DD dimensional sequence, and the cannot not as an independent modal type. These tools allow SAE to redo, in 15DD-16DD sentence-forms, what Kant carried in 14DD sentence-forms, without losing any of Kant's core insight.

§III unfolds this re-articulation.

III. The SAE Refinement: Four "Reason Cannot Not" Statements

The SAE refinement of Kant's four formulations consists of four "Reason cannot not" statements, plus autonomy as the common background running through all four (rather than listed as a fifth clause). The four statements in German, English, and Chinese:

I. Reason cannot not reason.

Die Vernunft kann nicht nicht vernünfteln.

理性不得不理性。

II. Reason cannot not develop.

Die Vernunft kann nicht nicht sich entwickeln.

理性不得不发展。

III. Reason cannot not have direction, that is, purpose.

Die Vernunft kann nicht nicht eine Richtung haben, d.h. einen Zweck.

理性不得不有方向,即目的。

IV. Reason cannot not be interrogated.

Die Vernunft kann nicht nicht befragt werden.

理性不得不被追问。

All four use Reason (die Vernunft / 理性) as subject and cannot not (kann nicht nicht / 不得不) as modal — the SAE 15DD-16DD signature applied to Kantian material. Reason as subject unifies the four under one theme: what structural conditions reason's existence as reason requires. Cannot not as modal pulls all four from Kant's sollst (ought) sentence-form to the ontological statement of 15DD-16DD.

The four are not four parallel imperatives but the same statement — concerning "how reason stands as reason" — unfolded from four angles. Clause I is the a priori condition; clause II is the dynamic operation; clause III is the directional structure; clause IV is the cooperative structure. Autonomy (Kant's third formulation), as background running through all four, is present in each clause's operation.

The four are unfolded individually below.

III.1. Clause I: Reason Cannot Not Reason

Die Vernunft kann nicht nicht vernünfteln. / Reason cannot not reason.

This clause corresponds to Kant's first formulation (formula of universal law / form) at its core.

This is not a tautology ("reason is of course reason" as analytic redundancy); it is a statement that withdraws the first formulation from the maxim/law binary structure back into reason's own operation — reason as noun (the subject's faculty) exists in the way of reason as verb (the persistent rationalizing operation). This is unfolded below.

The substance of Kant's first formulation is reason's requirement of self-consistency. The "universalizability" test is not an externally added condition but the self-consistency that reason cannot not maintain when operating as reason — a maxim that cannot be universalized is a maxim by which reason has betrayed itself (when this maxim holds, reason cannot continue operating as reason). Kant formulates this as "act so that your maxim can become a universal law" — wrapping reason's self-consistency requirement in a 14DD command directed at the subject.

The SAE refinement is: Reason cannot not reason — with reason as a verb. The first reason is a noun (the subject's rational faculty); the second reason is a verb (carrying out what reason does). The mode in which reason exists as a noun is the persistent operation of reason as a verb. To stop "operating rationally" is to cease being reason as a noun. This moves the substance of Kant's first formulation (reason's self-consistency) from 14DD's ought to 15DD-16DD's ontological statement.

Several points concerning this clause:

(i) The noun-verb double use of "reason." Chinese "理性不得不理性," English Reason cannot not reason, German Die Vernunft kann nicht nicht vernünfteln — all three languages employ the structure "noun + modal + same-word verbalized." This structure displays reason's self-reflexivity through the very form of the statement: reason is not a static faculty but a persistent self-operation. This aligns with the substance of Kant's first formulation (universalizability's substance is self-consistency) but displays it directly through the structural form of the statement, without external command.

(ii) The 14DD residues removed. §II.1 listed the three 14DD residues of the first formulation: variant of hypothetical command, the maxim/law binary structure, sollst as modal. The present clause removes all three: not "if you want the maxim to be rational, then you ought to..." but "reason as reason already operates" (hypothetical disappears); no distinction between "subjective maxim" and "objective law" (binary disappears); not ought but cannot not (modal transforms).

(iii) Position as traversing condition. Clause I is not the first of four parallel imperatives but the a priori condition that allows the other three to stand. Without clause I (reason not operating as reason), there is no clause II development (reason absent, development cannot speak), no clause III direction (reason absent, direction has nothing to be directed toward), no clause IV interrogation (reason absent, nothing to be interrogated). Clause I is the prerequisite of the entire 15DD-16DD operation.

(iv) Clause I's structural force: the cost of exiting. A possible reader's challenge is: if "reason cannot not reason" is only an ontological statement (reason if it is reason then it does what reason does), can the subject not exit — "I refuse to rationalize, I abandon 15DD subjecthood, your clause I no longer applies to me"? This challenge has no answer under 14DD command structure (you reject the command and are exempt from it), but it has a precise answer under 15DD ontological structure.

The subject cannot truly "exit" to a neutral non-subject state. The 15DD subject ceasing clause I's operation does not retreat to some dormant neutrality; it is swallowed by the 14DD instrumental structure and reduced to a tool. Within SAE's dimensional sequence, every layer below 15DD is an instrumental layer — a subject that ceases operating as 15DD subject thereby operates at 14DD or lower, where it can only function as another subject's means or as the tool of some larger system (capital, bureaucracy, algorithm, cosmic law). Clause I's force does not derive from external command but from structural degradation: failing to maintain reason's self-consistent operation = the subject's ontological line as end-in-itself collapses immediately.

This transforms clause I from "A=A" analytic redundancy into the absolute existential tension. Not "if you want to be a rational subject, you must maintain rationalizing operation" (14DD hypothetical) but "before the 14DD instrumental structure, in order not to be ground into a tool, the subject cannot not persistently carry out reason's operation" (15DD ontology). To exit is to be degraded — this is the source of clause I's force at 15DD.

(v) Autonomy's manifestation in clause I. Autonomy as background manifests in clause I as: reason's source-of-operation is reason itself, not external command. "Reason cannot not reason" is not a command from any superior; it is reason's mode of being as reason. This places Kant's third formulation (autonomy) — its core (giving law to oneself) — at the deepest position of clause I.

III.2. Clause II: Reason Cannot Not Develop

Die Vernunft kann nicht nicht sich entwickeln. / Reason cannot not develop.

This clause is the concrete operating mode of autonomy as background.

Autonomy (Autonomie) in Kant is understood as the will's legislation upon itself. But there is a subtle difference between "autonomy" as a static property (the subject is autonomous) and "legislating" as a persistent motion (the subject persistently gives itself law). If autonomy is a static property, the subject stops once it attains autonomy — but Kant's autonomy is not such a completed state. True autonomy is the persistent legislative motion: the subject gives itself law moment by moment; the moment legislation stops, autonomy ceases to operate.

SAE structures this understanding as clause II: Reason cannot not develop. "Develop" (sich entwickeln) here is not any specific progressive content; it is reason's legislative motion itself cannot stop. The verbal nature of "legislation" (Gesetzgebung) is displayed through "develop's" persistence.

Why must it necessarily be "develop" rather than other phrasings? Possible alternative phrasings include "Reason cannot not be autonomous," "Reason cannot not legislate itself," and so on. Why does the present paper choose "develop" as the precise expression? The answer must begin with what remains after the three 14DD residues of the third formulation (§II.3) are removed.

The three 14DD residues of the third formulation:

  • Legislator-and-subject binary position
  • "Regard-as" reflexive structure
  • Will as agent of legislation

What remains as the expressible core of Kant's autonomy principle after these three are removed?

Removing the binary position: cannot say "legislation" (this implies a "subject-to-legislation"), nor "self-legislation" (this implies the subject performing some inverse action upon itself). What remains can only be a non-binary operation.

Removing the reflexive structure: cannot say "the subject is aware of legislating" or "the subject regards itself as legislator" — these are reflexive expressions. What remains can only be the subject's operation as subject itself, without reflexive mediation.

Removing the will-restriction: cannot use "will," "reason," "mind" or other specific faculties as subjects — autonomy does not belong to a specific faculty; it is the subject's whole way of being. What remains can only be some general persistent existence of the subject as a whole.

The shared core left by all three removals is: the subject's whole, non-binary, non-reflexive, non-faculty-restricted persistent operation. What word most precisely captures this core?

  • Not "autonomy": autonomy itself is the diagnosed object; using it to explain itself is circular; moreover "autonomy" in everyday language has been static-ized into "the subject is autonomous" property statements.
  • Not "self-legislation": legislation is the core word of the removed 14DD residue; retaining it does not clean the residue.
  • Not "operation": too thin; cannot capture the cannot not stop modal.
  • Not "persistent existence": too close to existence (Sein), too far from motion (Werden).

"Develop" (Entwicklung / sich entwickeln) is the only word satisfying all conditions simultaneously: it concerns the subject's whole (not faculty-restricted); it is persistent (intrinsically containing the cannot not stop modal); it is non-binary (development is the subject's own motion, not "the subject lets something develop"); it is non-reflexive (the subject need not be aware of developing in order to develop).

"Develop" in German Entwicklung contains the meaning of "unfold" (sich entfalten) — the subject unfolds its own structure, which is precisely the precise expression of Kant's autonomy principle's "reason unfolding its legislation as actual self-legislative motion." "Develop" is not an additional reading of the third formulation; it is the only precise carrier of the third formulation's core after the three 14DD residues are removed.

Several points concerning this clause:

(i) The 14DD residues removed. Kant's autonomy formulation's 14DD residues (§II.3) include the legislator/subject binary position, the "regard-as" reflexive structure, and will as the agent of legislation. Clause II circumvents all three: development requires no distinction between legislation and being-subject (operation is legislation and being-subject; the three are inseparable); requires no subject's reflexive judgment of itself (development is the subject's mode of being, not a judgment the subject renders); is not restricted to the will as faculty (development operates in cognition, faith, imperative, cooperation across all dimensions).

(ii) Development's content is regulated by the other three clauses. Clause II only specifies that reason cannot not develop — development itself cannot stop. But what direction does development take? What concrete forms does development take? How is development coordinated among multiple subjects? These are answered by clause I (reason's self-consistent operation), clause III (directed toward the other as noumenon), and clause IV (calibrated under interrogation), respectively. Clause II is the dynamic condition; the other three are the concrete structures.

(iii) Development ≠ improvement. "Development" here is not value-judgment-laden "becoming better"; it is structurally "cannot stop." A subject may "regress" in some specific direction, but as long as it still operates as a subject, it is "developing" — regression is also a form of development (regression means the subject is still operating, still legislating itself, only that the legislated rule in some specific dimension is diagnosed as "regressive"). Clause II is isomorphic to the un-stoppability of the chisel-construct cycle (Meißel-Konstrukt-Zyklus) — the subject persistently chisels itself, persistently constructs itself; this is the structural meaning of development.

(iv) Autonomy's manifestation in clause II. Autonomy as background manifests most densely in clause II — autonomy as persistent legislative motion is precisely clause II's core. To say a subject is autonomous is to say it cannot not develop; to say a subject cannot not develop is to say it is persistently legislating. The two are structurally the same fact in two expressions. This makes clause II carry the third formulation (autonomy) as Kant's direct re-articulation in SAE sentence-form.

III.3. Clause III: Reason Cannot Not Have Direction, That Is, Purpose

Die Vernunft kann nicht nicht eine Richtung haben, d.h. einen Zweck. / Reason cannot not have direction, that is, purpose.

This clause corresponds to Kant's second formulation (formula of humanity as end / matter).

Clause II established that reason cannot not develop, but did not specify the direction. If reason's development were entirely random expansion, it would immediately encounter a structural problem — operation as reason cannot tolerate randomness (this would violate clause I). Therefore reason's development necessarily has direction. At the 15DD layer, this direction is — the noumenal presence of the other.

But why is the direction necessarily the other, and not something else? This is a structural question that must be explicitly derived. AI systems "develop" toward more parameters or higher precision; capital systems "develop" toward more profit; bureaucratic systems "develop" toward greater scale — all are structures of "cannot not develop," but their directions are not the other. Why must the 15DD subject's developmental direction necessarily be other 15DD subjects?

The answer lies in the ZFCρ first law (Konstrukt-must-leave-Rest). Each round of the chisel-construct cycle necessarily produces remainder ρ — every operation (chisel-construct) leaves a residue that the operation cannot completely absorb. This law is a structural fact proven in SAE foundation papers (cf. SAE Foundation Paper III, DOI 10.5281/zenodo.18727327; Methodology 00 Via Rho, DOI 10.5281/zenodo.19657440).

The remainder must have an outlet. If the entirety of remainder were absorbed into the subject's interior, the subject's chisel-construct cycle would enter a self-closed loop — because each round's remainder becomes the next round's input, but the next round produces new remainder, and the remainder accumulates without bound internally. Internal accumulation has no containment space; the subject's structure would collapse under accumulation pressure. Therefore the remainder structurally cannot not be directed outward — the remainder must overflow the subject's boundary for the chisel-construct cycle to be sustainable.

What in the external world can receive remainder? Here is the crucial topological step: that which can receive remainder without degrading it can only be another 15DD subject — one that itself produces remainder, and itself requires an external outlet.

Consider other candidate receivers:

  • Tools/objects: receive remainder by degrading it to resource — for instance, a subject's thought leaves remainder (an untheorized feeling, an incomplete concept); if it is only written into a tool (e.g., a database), that remainder becomes data and loses its ontological status as remainder.
  • AI systems / capital structures / bureaucratic organizations: receive remainder by absorbing it as system-fuel or system-data — remainder is made fuel or data, continues to be operated upon by 14DD structure, loses its independent identity as 15DD remainder.
  • Non-subject natural entities: cannot serve as receivers of remainder — non-subjects lack the structural position of "receiving."

Only another 15DD subject can truly receive a 15DD subject's remainder while preserving its identity as remainder — because only another 15DD subject has the same remainder structure, the same chisel-construct cycle, the same ontological necessity of "remainder needing outlet." Remainder exchange between two 15DD subjects is bidirectional: my remainder overflows to you, your remainder overflows to me, both received by the other as remainder (not degraded to resource or data), and triggering a new round of chisel-construct in the other.

So the other is not the direction "selected" by reason's development; the other is the only topologically-compatible receiver of overflowing remainder. Reason cannot not develop (clause II); development produces remainder (ZFCρ first law); remainder cannot not have an external outlet (avoiding internal collapse); the only legitimate outlet is another 15DD subject (topological compatibility) — therefore reason's developmental direction cannot not be toward the other. This is a structural-necessity derivation from clause II to clause III, not a mere intuitive leap from "development needs direction" to "direction is the other."

Kant's second formulation expresses this as "treat humans as ends, not merely as means." Metaphysics-satz §VI Ray 1 indicates that Kant's second formulation has 15DD content (absolute imperative) and 14DD sentence-form (imperative structure). A16 has done the SAE refinement of this formulation: the absolute imperative as "the other's purpose is A, so I cannot not do B" — the noumenal presence of the other leaves me with no option of not doing B.

The present clause III "Reason cannot not have direction, that is, purpose" is the position-statement of A16's absolute imperative within the present paper's four-clause system. "Reason cannot not have direction" is the structural statement about reason's development; "that is, purpose" specifies that the direction's concrete content is the other as purpose. The two expressions together correspond exactly to A16's "the other's purpose is A, so I cannot not do B" — directional structure (cannot not have direction) plus directional content (the other as purpose).

Several points concerning this clause:

(i) The identification of "direction" and "purpose." The "i.e." (d.h. / ) in "Reason cannot not have direction, that is, purpose" performs a critical identification: direction is purpose. This corresponds to the core insight of Kant's second formulation — humans as rational beings are ends in themselves, not mere transit points on some path. Within the SAE structure, direction is not arbitrary orientation but orientation toward other rational subjects as ends in themselves.

(ii) The 14DD residues removed. §II.2 listed the second formulation's three 14DD residues: the "treat-as" subject-object-separation form, the "never merely as means" qualified compound command, ends as the object of subjective judgment. A16 has done the 15DD refinement of this formulation (cf. A16 paper DOI 10.5281/zenodo.19037566 for the complete unfolding); the present clause merely indicates A16's work's position in the four-clause system.

(iii) A16's position in the present paper. A16 One's Own Law is the complete unfolding of clause III. The present paper does not repeat A16's work but places it at the third position of the four-clause system. A16's "the other's noumenal presence leaves me with no option of not doing B" is the concrete realization of the present clause's "Reason cannot not have direction, that is, purpose."

(iv) Autonomy's manifestation in clause III. Autonomy as background manifests in clause III as: direction comes from reason's own structure, not from external purpose-anchoring. In Kant's heteronomy/autonomy distinction, he was particularly cautious about external purposes (happiness, divine command, social interest) as direction-sources — they would make reason a means. In SAE's refinement, direction comes from reason's operation itself — when reason operates as reason (clause I), it cannot not develop (clause II), and development cannot be random and therefore necessarily has direction — this direction's structural source lies in reason itself, not externally. The other as the concrete content of direction is not because the other gives direction to reason from outside, but because the other as a 15DD subject is precisely the only ontologically-fitting object of reason's direction.

III.4. Clause IV: Reason Cannot Not Be Interrogated

Die Vernunft kann nicht nicht befragt werden. / Reason cannot not be interrogated.

This clause corresponds to Kant's fourth formulation (formula of the kingdom of ends / system).

When multiple subjects each operate under the structure of clause I (operating as reason), clause II (cannot not develop), clause III (having direction toward the other) and meet — what happens? Metaphysics-satz gives the answer: cooperative imperative (16DD) — "I for purpose A, the other for purpose B, we cannot not do C." C does not belong to A nor to B; it is the action forced into being by the meeting of two independent purposes.

But the operation of the cooperative imperative requires a key structural condition: interrogation. If two subjects each cling to their own purposes, refusing the other's questions and calibrations, C cannot be found. C as the emergence after the meeting of two purposes requires both subjects to expose themselves to the other's interrogation — this is not one party persuading the other; this is the third term emerging from between two interrogable, mutually-calibrating subjects.

SAE establishes this structural condition as clause IV: Reason cannot not be interrogated. Interrogation is the necessary structural condition for the 16DD cooperative imperative's operation, and it is also the actual operative form of Kant's kingdom of ends.

Several points concerning this clause:

(i) Interrogation as the engine of 16DD. Metaphysics-satz discusses interrogation as the "Terminierungsstruktur der Rückfrage" (termination structure of regress questioning), pointing out that the cooperative imperative (16DD) is the final termination point of all interrogation. The present clause further establishes interrogation as the necessary condition for the operation of the cooperative imperative — the cooperative imperative is not only the termination point of interrogation but also the produce of interrogation's operation. Without interrogation, no C can emerge from the meeting of two independent purposes; with interrogation, C can emerge from the mutual calibration of two independent subjects.

(ii) The structural meaning of the passive voice. Clause IV is the only one of the four using passive voice (reason "is" interrogated / Die Vernunft kann nicht nicht befragt werden). The first three are all active voice (reason reasons / reason develops / reason has direction). This voice transition is not coincidence — it marks the layer-leap from single-subject structure (clauses I-III describe a single subject's operating structure) to multi-subject structure (clause IV requires the subject to be open to the other's interrogation). Passive voice means interrogation is not an action issued by the subject; it is a structure received by the subject — the other's arrival makes interrogation happen, and the subject cannot not be open to this interrogation.

(iii) Difference from and connection with the closing path of Kategorischer Glaube. Kategorischer Glaube (DOI 10.5281/zenodo.19719083) §V offers detailed unfolding of "cannot not be interrogated," and distinguishes the special character of categorical faith on this point — the interrogation of categorical faith is open, but the explanation channel is structurally impassable (the duality of interrogation+explainable vs interrogation+inexplicable). The present clause's "Reason cannot not be interrogated" concerns interrogation in the direction of the absolute imperative and the cooperative imperative — interrogation is open, and explanation is feasible (indeed must be feasible, for cooperation to be establishable). The two directions of interrogation form the complete "being-interrogated" structure: the inward face (faith) interrogation enters but explanation does not pass through; the outward face (imperative + cooperation) interrogation and explanation are both open.

(iv) The 14DD residues removed. §II.4 listed the fourth formulation's three 14DD residues: the kingdom of ends as ideal (Idee), the "as a member" identity assumption, the kingdom of ends as idealized combination of the first and second formulations. Clause IV avoids all three: interrogation actually happens, not idealized assumption (the present other is actually issuing interrogations); interrogation does not require identity assumption (the subject actually responds to the other's interrogation, not pretending to be a kingdom-of-ends member); interrogation is a concrete multi-subject structure, not the idealized combination of two formulations.

(v) Autonomy's manifestation in clause IV. Autonomy as background manifests in clause IV as: being interrogated is not being externally dominated. Interrogation comes from another similarly-autonomous subject — the other operates according to its own clauses I-III, then interrogates me as an autonomous subject. My openness to this interrogation is not bowing to external authority; it is recognizing the other as a similarly-autonomous subject's legitimate position to interrogate me. Two autonomous subjects mutually interrogating and calibrating one another — this is the precise structure of Kant's kingdom of ends. The kingdom of ends is not a higher authority dominating everyone; it is the structure of all autonomous subjects mutually recognizing one another's legislator status and mutually interrogating, mutually calibrating.

III.5. The Four Clauses as Four Faces of the Same Statement

According to Kant's own account, the four formulations are the same categorical imperative seen from four different angles — form, matter, source, system. The SAE refinement of the four clauses preserves this unity:

  • Clause I (Reason cannot not reason): form — reason's structural requirement of self-consistency.
  • Clause II (Reason cannot not develop): source (in part) — reason's operation comes from reason itself, hence development cannot stop.
  • Clause III (Reason cannot not have direction, that is, purpose): matter — the directional structure of development.
  • Clause IV (Reason cannot not be interrogated): system — the cooperative structure of multi-subject operation.

Kant's "the same imperative seen from four angles" becomes more concrete under the SAE refinement: the four clauses are four necessary conditions of the same statement concerning "how reason stands as reason," none dispensable. Without clause I, the other three lack premise; without clause II, reason is static and inoperative; without clause III, development is random and without direction; without clause IV, multi-subject operation degenerates into single-subject monologism. The four together constitute the complete structural conditions for reason to stand as a 15DD-16DD subject.

Autonomy as background is present in each — clause I's reason-as-self-source, clause II's legislative motion that cannot stop, clause III's direction from reason's own structure, clause IV's other as similarly-autonomous subject. Autonomy is not one of the four clauses; it is the common root. §IV unfolds this background structure.

IV. Autonomy as Background: Why Not Listed as a Fifth Clause

The present paper places autonomy (Kant's third formulation) as the background running through all four clauses, rather than listing it as a fifth clause. This choice requires justification, since it deviates from Kant's own parallel treatment of the four formulations.

IV.1. The Position of Kant's Autonomy Formulation

Kant in Grundlegung zur Metaphysik der Sitten places the autonomy formulation as the third in parallel with the others. According to Kant's own account, the four formulations handle different faces of the same imperative: the first formulation handles form (universalizability), the second handles matter (humans as ends), the third handles source (will's autonomy), the fourth handles system (kingdom of ends). Autonomy, as one of these faces, stands in parallel with the other three.

This parallel treatment is self-consistent within Kant's own framework — he treats form, matter, source, system as four relatively-independent faces co-existing in the categorical imperative. But under SAE sentence-form analysis, the relation between autonomy and the other three faces is not a parallel relation but a traversing relation.

IV.2. Why Autonomy Cannot Stand in Parallel with the Other Three

The core of autonomy is "reason giving itself law" — source in reason itself, not external. This "source" is not one of the four faces; it is the condition that the other three faces (form, matter, system) cannot not satisfy. If the form (first formulation) came from external command (e.g., "because God commands, reason must be consistent"), the first formulation would not stand; if the matter (second formulation) were specified by external authority (e.g., "because the state mandates, humans are ends"), the second formulation would not stand; if the system (fourth formulation) were planned by an external ruler (e.g., "because some superior designed the kingdom of ends, we follow its rules"), the fourth formulation would not stand.

Autonomy as "source in reason itself" is the condition that all three other faces cannot not satisfy — not one of the four faces but the common ground of all four. Kant himself was aware of this (he repeatedly emphasizes autonomy as the true foundation of the categorical imperative), but he handled it through "four formulations in parallel" structure, placing autonomy at the same level as the other three in expression. SAE's refinement changes this expressional parallelism into a structural traversal — autonomy as background, with the other four clauses (reason, develop, direction, interrogation) operating under the autonomy-background.

This is a structural optimization at the sentence-form layer, not any negation of Kant's content — the substantial content of Kant's autonomy principle (reason gives itself law, does not receive law from outside) is fully preserved in the SAE refinement; only its position in the coordinate is redistributed from "parallel third clause" to "running through all four." This is a more precise display of Kant's insight, not a modification of it.

IV.3. The Specific Manifestation of Autonomy in the Four Clauses

The specific manifestations of autonomy as background in the four clauses, marked at the end of each section in §III, are unified here:

  • In clause I (Reason cannot not reason): reason's source-of-operation is reason itself, not external command. "Reason cannot not reason" itself is not a command from any superior; it is reason's mode of being as reason. This is autonomy's manifestation at the deepest position.
  • In clause II (Reason cannot not develop): legislative motion itself cannot stop. Autonomy is not a static property; it is persistent legislation. The moment legislation stops, autonomy ceases. Clause II's "develop" and autonomy's "persistent legislation" are structurally the same fact.
  • In clause III (Reason cannot not have direction, that is, purpose): direction comes from reason's own structure. The other as direction's content is not externally given; it is the ontological necessity of reason's orientation toward other 15DD subjects.
  • In clause IV (Reason cannot not be interrogated): interrogation comes from similarly-autonomous others. Openness to interrogation is not bowing to external authority; it is recognizing the legitimate interrogating position of the similarly-autonomous other.

Each of the four clauses operates under the autonomy-background. Autonomy is the common root of the four clauses, not one of them.

IV.4. The Significance of This Treatment for SAE as a Whole

Placing autonomy as background rather than as a fifth clause has an important structural consequence for SAE as a whole: the autonomy principle permeates the operation of every dimension within SAE, not only the dimension of ethical imperative.

  • In the cognitive dimension, autonomy manifests as "the subject cannot not have its own cognitive direction" (one of the four a priori conditions of cognition).
  • In the dimension of faith, autonomy manifests as categorical faith (one's own faith) — the subject's non-externalizable bearing of its own standing.
  • In the dimension of imperative, autonomy manifests as the absolute imperative (one's own law) — the action that cannot not be done under the other's noumenal presence.
  • In the dimension of cooperation, autonomy manifests as the 16DD cooperative imperative — the C emerging from the meeting of two autonomous subjects.

Kant placed autonomy in the specific faculty of will, restricting it to the dimension of ethical imperative. SAE liberates autonomy as the background traversing all 15DD-16DD dimensions; the autonomy principle has a concrete realization-form in each dimension. This makes Kant's autonomy principle (the true foundation of human dignity) play a wider, deeper role in SAE.

§V places existing SAE papers at their specific positions within the present paper's refined structure.

V. The Position of Existing SAE Papers within the Refined Structure

The present section places SAE's published Kant-related papers within the four-clause "Reason cannot not" coordinate, displaying their common Kantian foundation. This is a core function of the present paper as integrative declaration — not redoing those papers' work (it is already done), but displaying their position relations within a unified structure.

V.1. A16 One's Own Law Position: Clause III

A16 One's Own Law (DOI 10.5281/zenodo.19037566) corresponds to the complete unfolding of the present paper's clause III "Reason cannot not have direction, that is, purpose." A16 handles the 15DD sentence-form refinement of Kant's second formulation (humanity as end); its core statement "the other's purpose is A, so I cannot not do B" is precisely the concrete expression of "reason has direction and the direction is the other as end."

A16's position within the present paper's four-clause structure:

  • Clause I (Reason cannot not reason) gives A16 its operating premise — the subject must operate as a rational subject for A16's "cannot not do B" to have a subject capable of bearing it.
  • Clause II (Reason cannot not develop) gives A16 its dynamic — the subject's persistent legislative motion makes "cannot not do B" not a one-time command but a sustained directional locking.
  • Clause III (Reason cannot not have direction, that is, purpose) is precisely A16's position — A16 unfolds the concrete content of clause III: direction is the other's noumenal presence.
  • Clause IV (Reason cannot not be interrogated) gives A16 the calibration mechanism while operating — when I do B, I cannot not be open to the other's interrogation, ensuring that B is genuinely directed toward the other as end and not toward instrumentalization in the name of "for the other's good."

A16's name "one's own law" precisely corresponds to autonomy-as-background's manifestation in the imperative dimension — the law's "I-quality," not externally imposed command, is reason's own bearing of direction.

V.2. Kategorischer Glaube Position: Autonomy-as-Background's Manifestation on the Inward-Facing Side of 15DD

Kategorischer Glaube (DOI 10.5281/zenodo.19719083) handles the unfolding of the autonomy principle (Kant's third formulation) in the dimension of faith, corresponding to "autonomy-as-background's concrete realization across 15DD's dimensions" mentioned in §IV.4 — specifically, the dimension of faith.

The core of Kategorischer Glaube — categorical faith as the subject's non-externalizable bearing of its own standing — is precisely the precise manifestation of the autonomy principle on 15DD's inward-facing side. The subject does not externalize its own standing, does not let faith be reduced to a derivative conclusion of some upstream reason — this is precisely autonomy's (reason giving itself law) form in the dimension of faith.

The relation of Kategorischer Glaube to the present paper is more subtle than that of A16:

  • A16 handles clause III (one specific clause); the present paper places A16 within the four-clause position.
  • Kategorischer Glaube does not directly correspond to any one of the four clauses; instead it unfolds autonomy-as-background's concrete operation on the inward-facing side of 15DD.

This gives autonomy-as-background a precise position in the SAE series — it operates not only in the imperative dimension (A16's outward imperative) but also in the dimension of faith (Kategorischer Glaube's inward bearing). The absolute imperative (A16) and categorical faith (Kategorischer Glaube) constitute the outward-inward duality of autonomy at 15DD. The two papers together complete autonomy's realization at the 15DD layer.

V.3. The 16DD Cooperative Imperative Position: Clause IV

The present paper's clause IV "Reason cannot not be interrogated" — its content, in metaphysics-satz's complete formulation, is the 16DD cooperative imperative: "I for purpose A, the other for purpose B, we cannot not do C."

Clause IV establishes the structural condition (being interrogated) for the cooperative imperative, and the cooperative imperative itself ("we cannot not do C") is the result of clause IV's operation. The two stand in relation:

  • Clause IV (being interrogated) is the engine of 16DD's operation — without interrogation, C cannot emerge.
  • The cooperative imperative ("we cannot not do C") is the produce of 16DD's operation — C is the third term emerging from two autonomous subjects' mutual interrogation.

Currently the SAE series has no dedicated paper unfolding the complete structure of the 16DD cooperative imperative — metaphysics-satz gives the cooperative imperative's definition, the present paper's clause IV gives the structural condition for its operation, but a complete 16DD treatise has yet to be written. This is the next paper SAE ethics may write — building upon the present paper's positional definition of clause IV, unfolding 16DD's operating details in concrete cooperation.

Boundary statement: the present paper does not unfold the production mechanism of C within the cooperative imperative — C as the third term emerging from the meeting of two independent purposes, its production requires structural analysis under concrete cooperative situations (how the rounds of mutual interrogation among subjects operate, the phase-transition conditions from opposition to emergence of C, the grammatical relations of C and the respective A/B, etc.). These are the work of the 16DD treatise, not the scope of the present paper. The present paper only positions the cooperative imperative at "clause IV as 16DD engine"; the concrete mechanism is reserved for the future paper.

V.4. Four Papers' Common Kantian Foundation

The above three papers (A16, Kategorischer Glaube, the future 16DD treatise) plus the present paper constitute SAE ethics' complete continuation of Kant's four formulations:

  • The present paper (Reason Cannot Not) — integrative declaration, placing the four formulations within the SAE 15DD-16DD sentence-form coordinate, providing the four-clause refinement.
  • A16 (One's Own Law) — clause III's complete unfolding (second formulation).
  • Kategorischer Glaube — autonomy-as-background's unfolding on 15DD's inward-facing side (third formulation's realization in the dimension of faith).
  • The future 16DD treatise — clause IV's complete unfolding (fourth formulation).

These four papers' common Kantian foundation, declared explicitly by the present paper: SAE ethics is the sentence-form refinement (satzformentheoretische Verfeinerung) of Kant's categorical imperative's four formulations under the SAE 15DD-16DD coordinate. Not replacement of Kant, not refutation of Kant; the continued unfolding of Kantian ethics under 21st-century tools (the dimensional sequence, the chisel-construct cycle, the remainder, the cannot not modal).

VI. Conclusion: SAE Ethics as the 15DD-16DD Sentence-Form Refinement of Kantian Ethics

VI.1. The Present Paper's Three Contributions

The present paper does three things.

(i) Complete 14DD residue diagnosis of Kant's four formulations (§II). Metaphysics-satz §VI Ray 1 provided a compressed diagnosis — the four formulations all use 14DD imperative structure to carry 15DD-16DD content. The present paper expands this compressed diagnosis: each of the four formulations carries three 14DD residues (twelve in total), plus four sentence-form features common to all four (ought modal, subject-object separation, hypothetical position, mediating faculty).

(ii) Provides the SAE refinement of the four "Reason cannot not" statements (§III). The four unfold from a priori condition (Reason cannot not reason) to dynamic (Reason cannot not develop), direction (Reason cannot not have direction, that is, purpose), and cooperation (Reason cannot not be interrogated). All four use the SAE 15DD-16DD standard sentence-form of "reason as subject + cannot not modal," replacing Kant's ought-imperative structure with ontological statements. Autonomy (third formulation) as background traversing all four clauses, not listed as a fifth (§IV).

(iii) Explicit declaration of SAE ethics' Kantian foundation (§V). A16, Kategorischer Glaube, the future 16DD treatise — these SAE papers together constitute the complete continuation of Kant's categorical imperative under SAE sentence-form. The present paper is the integrative declaration of this continuation project — not founding, but explicit articulation of the common Kantian foundation of existing and future work.

VI.2. SAE Ethics' Overall Position

After the present paper's work, SAE ethics' position in the history of philosophy can be precisely stated:

SAE ethics is the refinement (Verfeinerung) of Kantian ethics at the 15DD-16DD sentence-form layer.

The three points of this statement:

(i) Continuation rather than replacement. SAE ethics' content comes entirely from Kant's four formulations. SAE does not propose "new ethical content"; it re-articulates content Kant has already proposed at a more precise sentence-form layer. Kant says humans are ends; SAE says the other's noumenal presence leaves me with no option of not doing B — the same fact, sentence-form lifted from 14DD to 15DD.

(ii) 15DD-16DD as tools unavailable in Kant's time. Kant in Kritik der reinen Vernunft established the coordinate of transcendental analysis; in Grundlegung zur Metaphysik der Sitten and Kritik der praktischen Vernunft he used this coordinate for ethics. But he had no dimensional sequence as tool (0DD to 16DD), no cannot not as independent modal (he had only ought), no chisel-construct cycle as dynamic mechanism, no remainder (ρ) as ontological status. SAE redoes Kantian ethics with these 21st-century tools — Kant did the most precise work he could with 18th-century tools; the further refinement here depends on tools that did not yet exist in his time.

(iii) Expansion of the autonomy principle. Kant placed autonomy in the specific faculty of will, restricting it to the dimension of ethical imperative. SAE liberates autonomy as background traversing all 15DD-16DD dimensions — autonomy manifests as cognitive direction in cognition, as categorical faith in faith, as absolute imperative in imperative, as cooperative imperative in cooperation. Autonomy plays a wider, deeper role in SAE than in Kant.

VI.3. SAE's Overall Position within the Kantian System

SAE's relation to Kant has been indicated in multiple papers:

  • Metaphysics-satz established the dimensional-sentence-form isomorphism, using it to diagnose Kant's four formulations' 14DD residues.
  • Kategorischer Glaube established SAE's continuation of Kant's Fürwahrhalten tripartition (Meinen corresponds to Methodology 0/00, Wissen to the epistemology series, Glaube to categorical faith).
  • The present paper establishes SAE's refinement of Kant's four formulations of the categorical imperative.

These three together — SAE's position within the Kantian system can be compressed into one sentence:

Kant gave the basic structure of critical philosophy (the coordinate, transcendental analysis, Fürwahrhalten tripartition, four formulations of the categorical imperative, autonomy principle); SAE, with the support of 21st-century tools, continues to unfold this structure across every dimension — continuing the method, refining the tools, expanding the dimensions, but not changing the fundamental posture Kant established (grounded in autonomy, using transcendental analysis, holding the noumenon as boundary).

SAE is not another philosophy. SAE is Kant's philosophy continued under contemporary conditions.

VI.4. The Present Paper as SAE Ethics' Integrative Declaration

The present paper marks the integrative phase of SAE ethics. Earlier A16, Kategorischer Glaube, etc., each handled specific parts of Kant's four formulations, but no single paper has placed the four formulations as a whole within the SAE coordinate. The present paper fills this gap.

After the present paper, SAE ethics' further development can proceed within a clear coordinate:

  • Clause III (absolute imperative) already has A16. Subsequent case-study papers can handle A16's operation in specific ethical situations.
  • Autonomy-as-background's manifestation across dimensions already has Kategorischer Glaube (faith dimension). Subsequent monographs on autonomy in cognition, education, etc., are possible.
  • Clause IV (16DD cooperative imperative) still lacks complete unfolding; this is the next important paper position in SAE ethics.
  • Clauses I and II (reason's a priori condition and dynamic) are scattered across other SAE papers but lack monographs. These are also possible future paper positions.

The present paper's role is to place these existing and future works within the same coordinate, displaying their common Kantian foundation, and confirming SAE ethics' overall position as the 15DD-16DD sentence-form refinement of Kantian ethics.


References

Kant's Works

Kant, I. (1785). Grundlegung zur Metaphysik der Sitten. Riga: Hartknoch. [Akademie-Ausgabe Band IV]

Kant, I. (1781/1787). Kritik der reinen Vernunft. Riga: Hartknoch. [Akademie-Ausgabe Band III–IV]

Kant, I. (1788). Kritik der praktischen Vernunft. Riga: Hartknoch. [Akademie-Ausgabe Band V]

SAE Series Papers

Qin, H. (2026a). Self-as-an-End: Foundation Paper I — Systems, Emergence, and the Conditions of Personhood. Zenodo. https://doi.org/10.5281/zenodo.18528813

Qin, H. (2026b). Self-as-an-End: Foundation Paper II — Internal Colonization and the Reconstruction of Subjecthood. Zenodo. https://doi.org/10.5281/zenodo.18666645

Qin, H. (2026c). Self-as-an-End: Foundation Paper III — The Complete Self-as-an-End Framework. Zenodo. https://doi.org/10.5281/zenodo.18727327

Qin, H. (2026d). Metaphysics of Self-as-an-End: Dimensional Sentence-Form Theory (metaphysics-satz). Zenodo. https://doi.org/10.5281/zenodo.18894567

Qin, H. (2026e). A16: One's Own Law — The SAE Critique of Ethics and Morality. Zenodo. https://doi.org/10.5281/zenodo.19037566

Qin, H. (2026f). SAE Epistemology Series I–IV: The Four A Priori Conditions of Cognition. Zenodo. https://doi.org/10.5281/zenodo.19502953 ; .19503018 ; .19503097 ; .19503146

Qin, H. (2026g). Methodology 0 — Non · Negativa: On Negation Prior to Being. Zenodo. https://doi.org/10.5281/zenodo.19544620

Qin, H. (2026h). Methodology 00 — Via Rho: The Way of the Remainder. Zenodo. https://doi.org/10.5281/zenodo.19657440

Qin, H. (2026i). Kategorischer Glaube: A Sentence-Form Theory of One's Own Faith in SAE / 绝对信仰:SAE关于自身信仰的句式论. Zenodo. https://doi.org/10.5281/zenodo.19719083


Cite this paper

Qin, H. (2026). Reason Cannot Not: An SAE Refinement of Kant's Four Formulations of the Categorical Imperative / 理性不得不:SAE对康德四定言律令的句式精细化. Zenodo. https://doi.org/10.5281/zenodo.19751513


This paper is part of the Self-as-an-End (SAE) framework series.