The Beauty of Causation
因果之美
In June 1929 a charred wooden beam was dug out of a ruin in Arizona. Its tree rings joined two sequences of rings, and from then on the beams in many ruins of the American Southwest had dates. A dry year leaves a narrow ring, every later ring grows outside it, and nothing can change it; someone who can read rings cannot help seeing that dry year there, wrapped by every ring that came after. A subject who has seen this cannot not acknowledge: what has happened cannot become not having happened; it remains in what comes after, and what comes after thereby has a history. That sentence is the beauty of causation. It has three faces: completive beauty is a history set before our eyes; generative beauty is the present moment turning into the past, or people chiseling out which point made the difference and which came first; the beauty of the remainder is a gap drawn by what already stands: records point only to the past, while the fundamental equations mostly do not distinguish before from after, and what is missing is a special starting point. The paper says what causation is and is not (not necessary connection itself, not entropy, not "the future not yet written," and not sorrow at time having passed); what can pass for the beauty of causation (faked age, nostalgia that wants to go back, old is good, mere correlation, mere succession, the cult of decay), and the three sentences that have to be kept apart before a site of suffering; and what is left to each person. It traces where the question comes from, from Aristotle's before and after and the Buddhist teaching of dependent arising to today's debate over the arrow of time. It ends by handing on to the beauty of biology the question of how the same pattern carries on after its material has been replaced.
Keywords: beauty of causation, history, trace, dependence, completive beauty, generative beauty, beauty of the remainder, power of judgment, overlap, 4DD
1. A Slice of Tree Rings
Saw through a tree crosswise, and the cut face shows ring after ring, one ring a year. In a tree that grows on rainfall, a wet year makes a wide ring; a dry year makes a narrow one.[^1] Some trees have been through fire and keep a fire scar sealed in their rings.[^2] Every later ring grows outside the earlier ones. Whatever happens later cannot change the ring inside: if that year was dry, the ring is narrow.
Trees in one region go through the same rains and the same droughts, so the order of wide and narrow is roughly the same from tree to tree, like a line of writing made only of thick and thin strokes. At the beginning of the twentieth century the astronomer Douglass learned in Arizona to read this writing. Working back from living trees and linking year by year to older and older wood, he built a dated sequence of rings that reached back to AD 1260. From the ruins of old villages in the Southwest he also built a very long sequence of rings, but this sequence had no dates: it would not join the dated one, there seemed to be a gap between them, and no one could say in what year these ruins had been built.
In June 1929, at a small town in Arizona called Show Low, an expedition dug out of a ruin a charred wooden beam, numbered HH-39. Its rings pushed the dated sequence back to 1237, and all at once it could be seen that the two sequences had in fact been overlapping all along, by twenty-six years, from 1260 to 1286. Douglass wrote that they had thought there was a gap to bridge, when in fact they had closed it long before without knowing it.[^3] The undated sequence landed on the calendar, and from then on the beams in many ruins of the Southwest had dates.
A dry year, once it has passed, cannot become not having been dry; it stays in that ring, and every later ring grows outside it. Seven hundred years later a charred beam still holds those years. Someone who can read tree rings, looking at that piece of wood, cannot help seeing that dry year there, wrapped by every ring that came after. It is like reading: learning one's characters takes effort, but once one knows them, one cannot help reading a character set before one's eyes.
That point is what this paper is about.
This paper follows the reading set out in the general outline.[^4] A personal aesthetic is each person's own and comes from his own cannot-not; aesthetics is the part that subjects with judgment cannot not acknowledge together, here called the overlap. The overlap is large; what does not overlap is larger. The overlap is not everyone being obliged to agree: whoever looks cannot not see, and whoever has seen cannot not acknowledge. When someone says "it is beautiful," he is claiming that this time he has landed on the overlap, and that claim can be right or wrong. What settles out of an act of drawing a boundary is called a construct; what it cannot contain is called the remainder. The remainder gives a place where one can go on, and a direction; it pushes no one; whether to go depends on a person's own cannot-not.[^5] A beauty has two faces: when the construct has come into place, it is completive beauty, quiet; when the construct is being chiseled out, it is generative beauty, tense. The beauty of causation has a third face as well, the beauty of the remainder: some gaps have a shape of their own, drawn by what already stands. A ray is a direction of judgment, not a classification of objects: the same slice of tree rings can also be looked at from the direction of physics, or from the direction of biology. This paper asks about one direction only, how what has happened remains in what comes after, and what the power of judgment sees in that direction.
2. What Causation Is and Is Not
The causation this paper speaks of is one thing made of two. One is this: what has happened cannot be canceled. What comes after cannot reach back to what came before: whatever happens later cannot change the fact that that year was dry. The other is this: it remains in what comes after. What comes before has a hold on what comes after: that year's drought was written into that ring, and also into the shape the tree later grew into. There are two ways of remaining. One is leaving a mark: that narrow ring is the mark the drought left. The other is dependence: that ring grew in that year, and with little rain it was narrow; had that year not been dry, it would not have been narrow. Marks let people read what came before; dependence lets people see how what came before holds what comes after.
Put together, the two are one thing: something having a history. A history is not a date, nor a sentence of the form "once, things were so"; it is the shape in which what has happened remains in what comes after. This paper's construct is this.
So causation is not necessary connection itself. Someone will ask: you say you have seen causation; what is it you have seen? What one sees is the shape of marks, the shape of before and after, the shape of dependence: that ring grew in that year, and with little rain it was narrow. Whether some invisible bond ties them together is a very old question, taken up in Section 6 with Hume.
Nor is causation entropy. A broken cup does not put itself back together, a drop of ink spreading in water does not gather itself up again, heat flows from hot places to cold ones: this is the direction in which entropy increases, a law of physics, one way in which the world writes before and after. That what has happened cannot be canceled holds outside entropy too: a letter, once sent, can be read and read again, but can never become unsent. This paper's construct is this one thing, together with the shape in which it remains in what comes after. How far this remaining has to do with entropy is exactly the gap of Section 3 and the question of Section 7; this paper does not answer for physics.
Nor is causation "the future not yet written." What comes before can hold what comes after extremely finely. Reliable weather forecasts for the midlatitudes today reach about ten days; reduce today's initial errors by another order of magnitude, and at most five more days are gained.[^6] In 1963 Lorenz saw, in a very simple set of equations, that a system with deterministic equations can be sensitive in the extreme to tiny differences at its starting point.[^7] That the weather cannot be forecast beyond about two weeks is not because the future is still empty, but because what comes before constrains what comes after so finely that no record can keep up. From this it does not follow that the future is already fixed, nor that it is not yet fixed; this paper says neither.
Aristotle said that there are four answers to "why": what a thing is made of, what form it has, what set it moving, and what it is for.[^8] This paper takes only the road of before and after and of what sets things moving: how what comes before holds what comes after. The other three answers are not on this ray.
Nor is the beauty of causation sorrow at time having passed. Looking at old things, people feel longing, regret, or a sadness they cannot name. These are each person's own, and are taken up in Section 5. What this paper speaks of is what that feeling is facing: something happened, and it has remained.
3. The Beauty of Causation
Once a subject has seen how something remains in what comes after, he cannot not acknowledge:
What has happened cannot become not having happened; it remains in what comes after, and what comes after thereby has a history.
That sentence is the beauty of causation. The first half belongs to everything that has ever happened: no one can cancel it. It is the second half that makes it beauty: it did not disperse, it was written into what came after, and written legibly. Every piece of wood has a past; tree rings make that past a visible shape. What tree rings can show is that what has happened can be written into what comes after, and written legibly. They cannot show that everything that has left a trace is beautiful; the drought of that year was not beautiful; the beauty lies where the shape it left is seen.
There are three things here, and they have to be kept apart. One is having happened: that year was dry; that is the world's affair, and no one can change it. The second is remaining: the drought was written into that ring, and what came after varied with what came before. The third is the cannot-not of the one who sees: having read that ring, he cannot not acknowledge that here there is a history. Take away any one of the three, and it is not the beauty this sentence speaks of. If it never happened and only a manufactured look is left, that is faked age; if it happened but did not remain, or remained illegibly, there is nothing to see, and most things that happen pass away quietly in just this way; if no one sees, there is no one who cannot not acknowledge anything.
Why is it overlap and not preference? Someone who can read tree rings, looking at that piece of wood, and not using it to reckon the price of timber, cannot not see the same thing: that year was dry, and it is here. This does not depend on nationality, or on the era, or on whether he loves old things. On this ray, seeing takes two things: seeing how the trace was left, and seeing how what came after varied with what came before. Without the first, what one sees is only oldness; without the second, only succession.
Seeing can also go wrong. With a piece of furniture given a faked age, one may think one sees a hundred years, when that hundred years is not there. To say "it is beautiful" is to claim that this time one really has seen, and the claim can be wrong; when the furniture is found to be faked, what is withdrawn is that one claim; it does not mean that history cannot be seen.
On all three faces, the beauty falls where what has happened and what comes after join. On the completive face, the history is already set before our eyes. On the generative face, the joining is happening: the present moment is turning into the past, or people are chiseling out which point made the difference. On the face of the remainder, what already stands jointly draws a gap.
Completive beauty: a history set before our eyes. Tree rings are one kind. The strata in a cliff face are another: what is below settled first, what is above came later. The stone steps before an old temple gate, sunk in the middle: no single foot wore that hollow; every foot over several hundred years trod on it. An old letter is another kind: it can be read again and again, and each time it is set before one's eyes anew; but it was sent, and can never become unsent.
A ruin is another kind. Simmel says that in a ruin nature has turned the work of art into material for its own shaping, just as art had earlier taken nature as its material.[^9] The shape of a half-fallen wall is drawn by two things together: the form given it by those who built it, and the wind and rain that later took it apart bit by bit. He also says that the ruin creates the present form of a past life, not according to its contents or remains, but according to its being past as such.[^10] Standing before a ruin, what one sees is not what is missing, but the past as past, here. This does not say that all ruins are beautiful, nor that destruction is good; it says only that the shape that taking apart produces is also a kind of history.
These are all quiet. They ask nothing of anyone; they are there.
Generative beauty: a history taking shape, a difference being chiseled out. The generative face has two places, both of them a history being written into what comes after: in one, time is writing the present moment into the past; in the other, people arrange a comparison so that how what came before holds what comes after can be read.
One is on the side of the world: the present moment turning into the past. In late spring of the ninth year of Yonghe, Wang Xizhi and his friends gathered at the Orchid Pavilion in Shanyin, in Kuaiji, to drink and compose poems. He wrote a preface to the poems of that day, and wrote: "What once gave us joy has, between a glance down and a glance up, already become a trace of the past"; and: "Those who come after will look on today as we today look on the past."[^11] Both lines are in a disputed passage: the "Preface at the River" quoted in Liu Xiaobiao's commentary on the Shishuo xinyu lacks the whole passage from "Now, people's dealings with one another" to "will be moved by this writing."[^12] This paper reads only the text as given in the Jin shu, and does not rule on its authorship. What he saw: what once gave joy has, between a glance down and a glance up, already become a trace of the past; today too will be the past for those who come after. What is done in the present moment is, in the blink of an eye, beyond canceling, and is to be left to what comes after. The construct is being chiseled out, and the tension is in "between a glance down and a glance up." From this he was moved, and said "Alas!"; that is his own, and is taken up in Section 5.
The other is on the side of people: people chiseling out which point made the difference, and which came first.
In 1854 cholera broke out in London again. Snow suspected that cholera came through water. In south London there were two water companies whose customers lived intermingled in the same districts, mixed very finely. One, called the Lambeth company, had moved its intake upstream in 1852, and the water it drew had no London sewage in it;[^13] the other, called the Southwark and Vauxhall company, still did. Snow wrote that the experiment was on the grandest scale: no fewer than three hundred thousand people of both sexes, of every age and occupation, and of every rank and station, from gentlefolk down to the very poor, were divided into two groups without their choice, and in most cases without their knowledge; one group was supplied with water containing the sewage of London, the other with water free of it.[^14] What remained for him was only to check which company's water each household that suffered a death from cholera drank. When he checked, per ten thousand houses, there were three hundred and fifteen deaths from cholera among those supplied by the Southwark and Vauxhall company, and thirty-seven among those supplied by the Lambeth company.[^15]
The beauty is not in how many lives he later saved, nor in his later being proved right. It is in what that arrangement set out: the two groups differed only in the water, and the numbers of dead parted at exactly that point. Whoever has understood the arrangement cannot not see this. The arrangement cannot show what in the water was doing the harm.
Which came first can also be chiseled out this way. When bacteria meet a virus, most die, and a few survive and can resist it. Is this resistance called forth only after meeting the virus, or was it already there before? In 1943 Luria and Delbrück divided one kind of bacterium into many small portions, grew each separately, then put each into the virus and counted how many survived in each portion. If resistance came only on meeting the virus, the numbers surviving in each portion should be roughly the same, differing from one another only as sampling error does; if it arose by chance early in the growing, a portion in which it arose early would have many descendants, its count would be surprisingly large, and portion would differ from portion very widely. When they counted, the fluctuation from portion to portion went far beyond what sampling error could explain; their conclusion was that resistance is a heritable change in the bacteria, and that its occurrence is independent of the action of the virus.[^16] Which came first was read off a distribution of numbers: the past was written into the counts. In 2017 a reanalysis of the original data said that it ruled out an explanation by induction alone, but could not rule out both being at work.[^17] Seeing can go wrong, and can be corrected; the part that was seen remains. This paper looks at which came first being written into the fluctuations of the counts; how resistance is passed on generation after generation is a matter for the beauty of reproduction.
An experiment that finds no difference at all has also chiseled something out: this point makes no difference.
The beauty of the remainder: records point only to the past. Tree rings keep every past year; no ring keeps next year. Fossils, strata, footprints, letters, photographs all point to the past; there is nothing that is a record of the future. This is so ordinary that people seldom ask why.
Most of the fundamental equations of physics do not distinguish before from after: run a stretch of motion backward, and it mostly still obeys the laws. Statistical mechanics adds that disordered states outnumber ordered ones beyond all comparison. If one reasons back from today's state with these laws alone, the most probable past turns out, against expectation, to be more disordered than today; then tree rings, fossils and memories would all be flukes. For records to be records, one more sentence has to be added beyond the laws. Feynman said in a lecture that he thought it necessary to add to the physical laws the hypothesis that in the past the universe was more ordered, in the technical sense, than it is today.[^18] Albert later called it the "past hypothesis."[^19]
The gap is here: why was the starting point of the universe so special? This gap has a shape. It is not "the universe is mysterious," but a specific gap: a starting point of very low entropy. Its shape is drawn by three things that already stand, together: the equations that do not distinguish before from after, statistical mechanics, and the fact that all records point the same way. Without knowing the answer, one can still see what is missing. This gap can also be looked at from the direction of physics; this paper looks at it because, of the three things that draw it, one is exactly this paper's construct: every history faces the same way.
To report it as it is: some do not accept this shape of the gap. Earman holds that the past hypothesis is not even false: it has not yet become coherent enough to be false.[^20] The shape of the gap may also have to be redrawn. Whoever sees it is claiming that this time he has seen rightly, and the claim can be wrong. This paper does not answer for physics. The gap gives a place where one can go on, and a direction: cosmology asks what the universe was like at its beginning. It pushes no one. Someone looking at tree rings who for the first time wonders why rings keep only the past is seeing the reverse side of every history.
There is another kind of gap, smaller, which also has a shape. When the air pressure falls, the needle of the barometer drops, and a storm comes too. From the observed correlations alone, three arrangements cannot be told apart: the pressure drives both the needle and the storm; the needle drives the pressure, and the pressure the storm; the storm drives the pressure, and the pressure the needle. All three arrangements give the same correlations: needle and storm change together, and once the pressure is known, the two are no longer correlated. Verma and Pearl proved that two causal diagrams cannot be told apart from the observed correlations alone if and only if they have the same links, and also the same places where two arrows meet head to head while their tails are not linked to each other.[^21] So the shape of this gap is quite clear: exactly these three, no more and no fewer. A fourth arrangement, in which needle and storm together drive the pressure, has already been ruled out by the data: in that case needle and storm would be uncorrelated to begin with, and would become correlated once the pressure is known. Move the needle by hand and the storm still does not come, and the arrangement in which the needle drives the pressure is removed; the storm always comes after the pressure has fallen, and the arrangement in which the storm drives the pressure is removed too. The one that remains was chiseled out by an intervention and a sequence together. This brings us back to generative beauty.
4. What Can Pass for It
The method is still the same: take it away and see.
Faked age. Newly made tables and chairs, worked over with rasps, fire and chemicals to give them wear and patina, look just like pieces used for a hundred years. Take away "it happened," and those traces are not of that hundred years; they are a look made in one go. What someone who can tell cannot not see is exactly this: its history is a different one, rasps and chemicals, one afternoon. Faking age can be a craft, and can be pretty; it simply is not the beauty of causation.
Nostalgia that wants to go back. Boym divides nostalgia into two kinds: one wants to rebuild the lost home and patch up the break; the other knows it cannot go back and dwells in the longing itself.[^22] The first wants cancellation: to erase what has happened and return to how things were. If it succeeded, the traces would be gone, and the history with them. It faces exactly what the beauty of causation looks at, and wants to take it away. The second cancels nothing; it is each person's own, and is taken up in Section 5.
Old is good; a famous person used it. The price of an antique, a famous person's former home, a bowl said to have been used by some great master. Take away price and fame and see: is the weathered shape still there? If it is, what one sees is the shape; if not, what one saw was price and fame.
Mere correlation. When the barometer needle drops, a storm comes. But move the needle by hand, and no storm comes. The needle is not a mark left by the storm, and the storm does not come because of the needle. The two change together because the same thing behind them is driving both: the air pressure. Take away that common thing, and nothing is left between the two.
Mere succession. The rooster crows and the sun comes up. Take the rooster away and see: the sun still comes up. Succession is not dependence.
The cult of decay. There is a taste that loves only the broken, the peeling and the rusted, loves them so much that it wants new things made old as well. To swap an attachment to wholeness for an attachment to decay is still attachment. Take away the ruler that says "decay is good" and see: in a peeling wall, are you seeing how time has worked on it, or a look you loved beforehand? The first is seeing; the second is a ruler, and the ruler is not what you see.
Before a site of suffering, three sentences run together. On 6 August 1945 an atomic bomb exploded over Hiroshima. About a hundred and sixty meters from the hypocenter stood an exhibition hall built in 1915; it was blasted down to broken walls and the iron frame of its dome, but did not fall. In 1966 the Hiroshima City Council passed a resolution calling for its preservation; in 1996 it was inscribed as a World Heritage site, and it is still kept as it was just after the bombing.[^23]
Standing before it, one has to keep three sentences apart. The first: I see the shape of these breaks, why only this much of the steel frame is left, why the wall breaks off here, what shape the force of that instant left. This is the business of aesthetics; whoever looks cannot not see. The second: it is beautiful. This claims that the first sentence has truly seen: what is seen is the shape left by the force of that instant, not the suffering itself; the claim can be wrong. Few people stop there to look at the shape; most stop to mourn and to remember, and that is not the business of aesthetics, which does not weigh itself against it either. What those who have looked at the shape cannot not acknowledge together may be only this shape; the overlap is narrow. The third: it ought to be preserved. This is a matter for ethics, and aesthetics does not rule on it; beauty gives no one power to dispose over others. If the three sentences run together into one, some will use the first two to decide the third, or use the third to forbid the first two. Once they are kept apart, Benjamin's question (taken up in Section 6) is neither answered by the first sentence nor impersonated by the second.
Neighboring rays. The beauty of physics looks at how the world answers form at its point of necessity; where the law that heat flows from hot to cold is answered by the world is the affair of that ray. This paper looks at how what has happened remains in what comes after. Both rays have experiments: an experiment in the beauty of physics looks at whether the world answers at the form's point of necessity; an experiment in this paper looks at which point made the difference and which came first. In Snow's case there was no equation waiting for the world to answer; what he was looking for was that point. The beauty of hundun looks at what all distinctions together have not secured; that the weather cannot be forecast beyond two weeks, as Section 2 has said, is this paper's affair, and the kind of system that dynamics calls chaotic is not the hundun of the beauty of hundun. The beauty of cognition looks at the past in memory: a person remembers the courtyard of his childhood, and that past is in his mind; this paper looks at the past remaining in things: the rings of the tree in that courtyard. The beauty of biology looks at how a pattern carries on after its material has been replaced; this is taken up in Section 7.
One last sentence, which this aesthetics says of every ray: beauty is not correctness, not usefulness, not importance, not understanding. Snow's discovery saved lives, which is usefulness and importance; working out how cholera spreads is understanding; that he was right is correctness. All of these have been set aside above. What is left is what the arrangement set out by itself.
5. What Is Left to Each Person
Which kind of history moves you is each person's own. Some love ruins, some love tree rings, some love an old letter, some spend their whole lives turning over archives.
Where to look is each person's own too. At Red Cliff, Su Shi said to his guest: look at it from the side of what changes, and heaven and earth do not stay still for even the blink of an eye; look at it from the side of what does not change, and things and I alike are without end.[^24] Looking at the same river, he could watch it flowing away, or still being there. Where to look and where to stop come from each person's own cannot-not; having looked, what one sees is the same river.
Wang Xizhi's sorrow, the aware (あはれ) of which Kenkō speaks, the taste one cannot put into words standing at the door of a former home: these are each person's own. This does not mean they do not matter: it is precisely they that lead most people to stop before old things. Once one has been led there and has stopped, the shape one sees is the overlap; the sorrow that arises from it is each person's own. The nostalgia that knows it cannot go back and dwells in the longing is each person's own too; it cancels nothing.
To say "this ruin is more beautiful than that one" is a judgment of beauty, and it can be discussed: does its shape set out one more stretch of history? Discussion may show that each has a history of its own, and then each keeps its own.
Aesthetics says only this: whoever has seen that shape cannot not acknowledge that it is beautiful; aesthetics decides for no one whether to stop for it.
6. Where the Question Comes From
That what has happened cannot be canceled, people have always known. To treat it as something one can stop and look at is recent, and the reasons for looking have been rewritten several times. First, before and after and "why" were given structure; then passing away became something one could stop and look at; in the eighteenth century people asked whether causation can be seen; in the nineteenth, age became a kind of value in things; then some asked how to face what is already so; and today the direction of time itself has become a scientific question. What follows runs in the order of these rewritings. For each figure, the paper reports faithfully what he discerned, why he looked, where he presses on this paper, and where this paper parts from him; other traditions appear in their own words.
Before and after, and "why." Aristotle says that time is the number of motion with respect to before and after.[^25] He looked in order to understand how nature changes, and discerned that before and after is a structure, not just one event next to another. He also distinguished four answers to "why," as Section 2 has said. He presses on this paper: a history is not only an earlier event, and writing only before and after leaves out the other three kinds of "why." This paper says plainly that it takes only the road of before and after and of what sets things moving.
Early Buddhism saw dependent arising: "when this exists, that exists; when this arises, that arises."[^26] Things arise dependent on conditions and cease dependent on conditions; what comes before has a hold on what comes after. It also saw impermanence. The Pali Dhammapada says: all conditioned things are impermanent; when one sees this with wisdom, one turns away from suffering, and this is the path of purification.[^27] Why did it look? To leave suffering and go toward purity, not to stop and admire. This is not a failing; it is another road. It presses on this paper: an attachment to the broken and the passing may be only another form of clinging. This was already tested in Section 4 by taking it away. This paper meets it in "when this exists, that exists": the dependence this paper speaks of is exactly this line. This paper parts from it over the purpose of looking: Buddhism looks in order to leave; this paper says only what those who have looked have seen.
By a river Confucius said: "What passes away is like this, never ceasing day or night!"[^28] What "what passes away" refers to has been read in different ways. Bao Xian's gloss: to pass is to go; everything that goes flows away like the river. Zhu Xi says that this is the transformation of heaven and earth: what goes passes on, what comes follows, without a moment's stop; this is the substance of the Way as it originally is.[^29] Why he looked varies with the reading. It presses on this paper: an image from which different schools read different things cannot be used as evidence. This paper only borrows the image, reading it close to Zhu Xi: what goes passes on, what comes follows; it does not use it as evidence that time has a direction.
Augustine says that the present of things past is memory; the present of things present is sight; the present of things future is expectation.[^30] He asked what time is, and discerned that the past appears as past only through memory. He presses on this paper: from the irreversibility of things alone one does not get "the past"; the past is past only when someone remembers it. This paper's answer has two layers. The past in memory is the affair of the beauty of cognition; this paper looks at the past remaining in things: tree rings need no one to remember that year for that year to be there. But for it to be seen as the past, someone has to look: the construct waits for no one; aesthetics waits for people.
Passing away becomes something one can stop and look at. Wang Xizhi's passage has already been told above. By setting traces of the past beside "those who come after will look on today," he extended history forward: today is the past of those to come. He presses on this paper: he organizes this experience through being moved, through pain and sorrow; take these away, and his piece is gone. This paper meets him in seeing; being moved and sorrow are left to each person.
In section 7 of Essays in Idleness Yoshida Kenkō says: 「世は定なきこそいみじけれ」, it is because the world is uncertain that it is precious; in the same section he asks what aware there would be if people never died.[^31] Section 137 asks again: 「花は盛に、月は隈なきをのみ見るものかは」, are we to look at blossoms only in full bloom, at the moon only when it is cloudless? He says that to long for the moon while facing the rain, or to draw the blinds and not know how far the spring has gone, has still more aware and more feeling; it is branches about to bloom and a garden strewn with fallen blossoms that are more worth seeing.[^32] He discerned that the moment of completion has no monopoly on being worth looking at; what has already fallen can also be stopped for and looked at. Why did he look? He says they are moving, and the word he uses is aware; take aware away, and he cannot go on. And the moon hidden by cloud is not irreversibility but concealment. This paper meets him in the fallen blossoms; his aware is his own.
Can causation be seen? Hume says that one event follows another, but we never can observe any tie between them; they seem conjoined, but never connected.[^33] He asked what grounds reasoning about matters of fact, and discerned that experience contains only succession and repeated conjunction, and that necessity comes from custom. His pressure on this paper is the most direct: you say you have seen the construct of causation; first say what it is you see. This paper's answer is in Section 2: what one sees is the shape of marks, of before and after, and of dependence, not necessity itself. Dependence, Hume himself wrote down. He defines a cause as an object followed by another, where all objects similar to the first are followed by objects similar to the second; or in other words, where, if the first object had not been, the second never would have existed.[^34] More than two hundred years later Lewis took the second half as the basis of a counterfactual analysis of causation.[^35]
In the Second Analogy Kant says that all alterations take place in accordance with the law of the connection of cause and effect. He gives two examples. Looking at a house, my perceptions can begin at the roof and end at the foundation, or the other way round; watching a ship go downstream, my perception of it downstream follows my perception of it upstream, and I cannot first see it downstream and then upstream.[^36] The order is fixed by the object, and I cannot change it. He wanted to show how experience is possible, and discerned that objective succession stands only by a rule. He presses on this paper: succession in the object cannot do without the rule of the one who looks, and to say "see" naively does not hold up. This paper meets him at that ship: the order is not up to the one who looks. It parts from him over the ground: he places the rule in the understanding; this paper says the order is fixed by what has happened itself.
Age becomes a value in things. Ruskin says that restoration means the most total destruction which a building can suffer; and: take proper care of your monuments, and you will not need to restore them.[^37] He discerned that the look can be copied, but the stretch of history in old stone cannot. He said it for the sake of preservation, and that is ethics first of all. This paper takes only one thing he saw: to make good the damage cancels the history the damage keeps; whether to preserve, aesthetics does not rule.
Riegl divides the values of monuments into several kinds, one of which is age value. He says that a monument's age value shows itself at a glance in its outdated appearance.[^38] He also says that we demand from the hand of man the making of complete works, as symbols of necessary and lawful becoming, and from nature working in time the taking apart of what is complete, as symbols of an equally necessary and lawful passing away.[^39] He discerned that without knowing in what year a wall was built, one can still see that time has worked on it. He presses on this paper: the "we" who make this demand are moderns, and this sensitivity to the traces of age is something that grew only in modern times. This paper's answer: that this sensitivity grew later does not mean it has been colonized; it may also be cultivation; whether the weathered shape is still there once antique price and fame are taken away is this paper's test. He also says that where the forces of nature act quietly and lawfully, a monument should not be withdrawn from their action; sudden violent destruction is not included.[^40] The dome at Hiroshima is of the latter kind. Before it, the sentence about seeing the shape still holds; but the traces there are wounds first of all, not age.
Simmel's ruin has also been told above. He discerned that a ruin is a new form drawn together by the original form and the force that takes it apart. He presses on this paper: what he speaks of is nature and spirit becoming one again in the ruin, not causation in general. What this paper takes is this: this shape is drawn by causation that has already run its course.
Two responses to what is already so. Nietzsche says: my formula for greatness in a human being is amor fati, love of fate: that one wants nothing to be other than it is, not forward, not backward, not in all eternity.[^41] Earlier, in The Gay Science, he said that he wanted to learn to see as beautiful what is necessary in things, and so to become one of those who make things beautiful.[^42] He discerned that the difficulty is not in knowing the past cannot be changed, but in affirming it. He presses on this paper: irreversibility is not automatically beautiful; and "making things beautiful" puts beauty back on the side of the one who looks. This paper parts from him in two places. First, the acknowledgment stops at the point of seeing; it does not require saying yes to a whole life, nor wishing it to come again. Second, what makes things beautiful is his personal aesthetic; the necessity he sees was not made by him.
In the ninth of his theses "On the Concept of History" Benjamin writes about a painting by Klee in which an angel faces the past. Where we see a chain of events, he sees a single catastrophe, which keeps piling wreckage upon wreckage and hurls it at his feet. He would like to stay, awaken the dead and make whole what has been smashed; but a storm blowing from Paradise drives him backward into the future. Benjamin writes: this storm is what we call progress.[^43] He discerned that what cannot be revoked is first of all suffering; irreversibility does not sift good from evil. He presses on this paper: if what has happened is the construct, this construct does not distinguish good from evil. This paper's answer is in the three sentences of Section 4: what this paper acknowledges is the shape that is seen, and it does not say that suffering is therefore good; how suffering is to be faced belongs to ethics, and aesthetics neither answers for it nor gives anyone the power to dispose of a site.
Today: the direction of time becomes a question. In 1928 Eddington wrote that he would use the phrase "time's arrow" to express this one-way property of time, which has no analogue in space.[^44] Today's discussion says that the fundamental dynamics hardly distinguishes before from after, and that the macroscopic direction has to be explained by statistics together with a low-entropy past; some hold that this past hypothesis solves the problem of direction, and some hold that it is not even false.[^45] This debate presses on this paper: "time has a direction" is not a precise enough statement; and the direction of causation is not simply the direction of entropy. This paper agrees: its construct is not entropy; that unsettled point is the beauty of the remainder of Section 3.
Since the end of the twentieth century Pearl, Woodward and others have treated causation as intervention: change one point and see whether another changes.[^46][^47] This presses on this paper: a causal model being elegant and its being right are two different things; whether a personal aesthetic can serve as evidence of truth is still disputed. This paper agrees that beauty cannot decide the case. The generative beauty this paper speaks of is not in a model's being pretty, but in what the arrangement sets out: apart from this one point, everything else is the same.
Boym's two kinds of nostalgia have already been used in Section 4. She presses on this paper: the study of nostalgia is about how people face the distance that irreversibility creates, and it cannot prove that irreversibility itself is beautiful. This paper agrees: nostalgia is on the side of the one who looks; the kind that wants to go back is one of this paper's ready-made counterfeits.
7. The Question Left Open
There is one question this paper does not answer: is the direction of causation simply the direction of entropy, and nothing else? The question is still debated today.[^48] This paper leaves it here; Section 8 says where this paper would be wrong if it is.
There is also one thing the ray of causation does not ask to begin with. What comes before holds what comes after; causation speaks of how, when one point changes, another follows. There is one thing it cannot say: how a pattern is still itself after its material has been replaced. A tree replaces many of its cells year after year and is still that tree; one cell divides into two, and both are still of its kind. What carries on? Causation answers "how things change," not "what carries on." A living thing keeps itself and passes itself on, and there is a share in it that the outside cannot fully account for; all this has to be asked with another way of looking.
Causation does not push anyone to ask this. A person can spend his whole life looking only at histories; if he cannot not ask how a pattern carries on after its material has been replaced, that is another ray. This ray stops here.
The question left open is: how the same pattern carries on after its material has been replaced. That is the beauty of biology.
8. What Would Make This Paper Wrong
If any one of four things held, this paper would be wrong. First, once longing, sorrow and fame are taken away, no shape at all is left before tree rings, ruins and old letters; then the beauty of causation would be only another name for a feeling. Second, "what has happened cannot be canceled, and it remains in what comes after" is shown to be only another way of saying that entropy increases, saying nothing beyond entropy; then this paper's construct would fall back into the beauty of physics, and this ray would not need to stand on its own. Third, once the physicists' debate and the sense of the universe's mystery are taken away from the gap of the low-entropy starting point, its shape goes with them; then the beauty of the remainder would be only a romance of the unknown. Fourth, before a site of suffering, the first sentence and the third cannot be kept apart: to say it is beautiful would amount to claiming it should be preserved, or to saying the suffering was good; then the division in Section 4 would be wrong, and aesthetics ought to fall silent there. This paper does not think any of these will happen, but it writes them here: a paper about "what has happened cannot be canceled" cannot cancel what it has said either; it can only be revised.
Acknowledgments
This paper is the fifth ray paper in the aesthetics branch of the SAE (Self-as-an-End) philosophical system and is published under the sole name of Han Qin. The author made the final decision on all philosophical arguments and choices, and alone is responsible for the final text.
Both drafting assistance and review were carried out with large language models. Drafting and internal precision audit were done by Claude (Anthropic); the structural gate and pre-publication sign-off were handled by ChatGPT (OpenAI). The material on the history of ideas used in Section 6, "Where the Question Comes From," was first gathered by ChatGPT's deep research, and its sources were then checked item by item. This paper, together with the second edition of the general outline and the other twelve ray papers, passed final review by both the internal precision audit and the structural gate, and passed a key-sentence acceptance check. The author thanks these systems and the research and engineering teams behind them. The author ruled on their comments one by one, and both acceptances and rejections are on record; the record of revisions and withdrawals across rounds is not reproduced here.
Notes
[^1]: National Centers for Environmental Information, "How Can Tree Rings Teach Us about Climate?," March 11, 2016, https://www.ncei.noaa.gov/news/how-can-tree-rings-teach-us-about-climate.
[^2]: U.S. Geological Survey, [cross-section of a fire-scarred ponderosa pine, Santa Fe watershed], image caption, August 19, 2016, https://www.usgs.gov/media/images/cross-section-fire-scarred-ponderosa-pine-sante-fe-wat.
[^3]: A. E. Douglass, "The Secret of the Southwest Solved by Talkative Tree Rings," National Geographic Magazine 56, no. 6 (December 1929): 737–770, at 764–767, 770.
[^4]: Han Qin, SAE Judgment and Aesthetics, 2nd ed. (2026), §5.1, "How to Read the Rays," DOI: 10.5281/zenodo.19296710.
[^5]: Han Qin, SAE: The First Critique (2026), DOI: 10.5281/zenodo.21439120.
[^6]: Fuqing Zhang et al., "What Is the Predictability Limit of Midlatitude Weather?," Journal of the Atmospheric Sciences 76, no. 4 (2019): 1077–1091, https://doi.org/10.1175/JAS-D-18-0269.1.
[^7]: Edward N. Lorenz, "Deterministic Nonperiodic Flow," Journal of the Atmospheric Sciences 20, no. 2 (1963): 130–141.
[^8]: W. D. Ross, ed., Aristotelis Physica (Oxford: Clarendon Press, 1960), II.3, 194b23–195a3; IV.11, 219b1–2.
[^9]: Georg Simmel, "Die Ruine," in Philosophische Kultur: Gesammelte Essais, 3rd ed. (Potsdam: Kiepenheuer, 1923), 138. First published in Der Tag (Berlin), no. 96, February 22, 1907.
[^10]: Simmel, "Die Ruine," 142–143.
[^11]: Fang Xuanling 房玄齡 et al., Jin shu 晉書, juan 80, "Biography of Wang Xizhi" 王羲之傳 (Beijing: Zhonghua shuju, 1974), 2099.
[^12]: Liu Yiqing 劉義慶, Shishuo xinyu 世說新語, "Qixian" 企羨, the "Linhe xu" 臨河敘 quoted in Liu Xiaobiao's 劉孝標 commentary, Sibu congkan edition.
[^13]: John Snow, On the Mode of Communication of Cholera, 2nd ed. (London: John Churchill, 1855), 68.
[^14]: Snow, On the Mode of Communication of Cholera, 74–75.
[^15]: Snow, On the Mode of Communication of Cholera, table IX, as reproduced in David Freedman, "From Association to Causation: Some Remarks on the History of Statistics," Statistical Science 14, no. 3 (1999), https://doi.org/10.1214/ss/1009212409.
[^16]: S. E. Luria and M. Delbrück, "Mutations of Bacteria from Virus Sensitivity to Virus Resistance," Genetics 28, no. 6 (1943): 491–511, at 494, 504, 509.
[^17]: Caroline M. Holmes et al., "Luria–Delbrück, Revisited: The Classic Experiment Does Not Rule Out Lamarckian Evolution," Physical Biology 14, no. 5 (2017): 055004, https://doi.org/10.1088/1478-3975/aa8230.
[^18]: Richard Feynman, The Character of Physical Law (Cambridge, MA: MIT Press, 1965), 116.
[^19]: David Z. Albert, Time and Chance (Cambridge, MA: Harvard University Press, 2000), chap. 4.
[^20]: John Earman, "The 'Past Hypothesis': Not Even False," Studies in History and Philosophy of Modern Physics 37, no. 3 (2006): 399–430, https://doi.org/10.1016/j.shpsb.2006.03.002.
[^21]: Thomas Verma and Judea Pearl, "Equivalence and Synthesis of Causal Models," in Uncertainty in Artificial Intelligence 6, ed. P. P. Bonissone et al. (Amsterdam: North-Holland, 1991), 255–268, theorem 1.
[^22]: Svetlana Boym, The Future of Nostalgia (New York: Basic Books, 2001), chaps. 4–5.
[^23]: City of Hiroshima 広島市, "Genbaku dōmu no rekishi" 原爆ドームの歴史, https://www.city.hiroshima.lg.jp/atomicbomb-peace/1036658/1021107/1015067.html; UNESCO World Heritage Centre, "Hiroshima Peace Memorial (Genbaku Dome)," https://whc.unesco.org/en/list/775.
[^24]: Su Shi 蘇軾, "Chibi fu" 赤壁賦, in Dongpo quanji 東坡全集, juan 33, Wenyuange Siku quanshu edition.
[^25]: Ross, Aristotelis Physica, IV.11, 219b1–2.
[^26]: Za ahan jing 雜阿含經, trans. Guṇabhadra 求那跋陀羅, juan 12, sūtra 298, Taishō shinshū daizōkyō, vol. 2, no. 99, 85a13–16.
[^27]: Dhammapada, v. 277, Mahāsaṅgīti Tipiṭaka edition, SuttaCentral, https://suttacentral.net/dhp273-289/pli/ms.
[^28]: He Yan 何晏, comp., with the subcommentary of Xing Bing 邢昺, Lunyu zhushu 論語注疏, juan 9, "Zihan" 子罕, Wenyuange Siku quanshu edition.
[^29]: Zhu Xi 朱熹, Lunyu jizhu 論語集注, juan 5, "Zihan" 子罕, in Sishu zhangju jizhu 四書章句集注, Wenyuange Siku quanshu edition.
[^30]: Augustine, Confessiones XI.20.26, ed. E. B. Pusey (Oxford, 1838).
[^31]: Yoshida Kenkō 吉田兼好, Tsurezuregusa 徒然草, sec. 7, in Tsukamoto Tetsuzō 塚本哲三, ed., Makura no sōshi, Hōjōki, Tsurezuregusa 枕草紙・方丈記・徒然草 (Tokyo: Yūhōdō Shoten, 1911), 320.
[^32]: Yoshida Kenkō, Tsurezuregusa, sec. 137, in Tsukamoto, Makura no sōshi, Hōjōki, Tsurezuregusa, 395.
[^33]: David Hume, An Enquiry concerning Human Understanding, ed. Tom L. Beauchamp (Oxford: Oxford University Press, 1999), 7.26.
[^34]: Hume, An Enquiry concerning Human Understanding, 7.29.
[^35]: David Lewis, "Causation," Journal of Philosophy 70, no. 17 (1973): 556–567, https://doi.org/10.2307/2025310.
[^36]: Immanuel Kant, Kritik der reinen Vernunft, B232, B235–238.
[^37]: John Ruskin, The Seven Lamps of Architecture (London: Smith, Elder, 1849), chap. 6, §§18–19.
[^38]: Alois Riegl, Der moderne Denkmalkultus: Sein Wesen und seine Entstehung (Wien und Leipzig: W. Braumüller, 1903), 22.
[^39]: Riegl, Der moderne Denkmalkultus, 24.
[^40]: Riegl, Der moderne Denkmalkultus, 25–26.
[^41]: Friedrich Nietzsche, Ecce homo: Wie man wird, was man ist (Leipzig: Insel, 1908), "Warum ich so klug bin," §10.
[^42]: Friedrich Nietzsche, Die fröhliche Wissenschaft, new ed. (Leipzig: E. W. Fritzsch, 1887), §276.
[^43]: Walter Benjamin, "Über den Begriff der Geschichte," thesis IX, in Gesammelte Schriften, vol. I.2, ed. Rolf Tiedemann and Hermann Schweppenhäuser (Frankfurt am Main: Suhrkamp, 1974).
[^44]: A. S. Eddington, The Nature of the Physical World (Cambridge: Cambridge University Press, 1928), 69.
[^45]: Craig Callender, "Thermodynamic Asymmetry in Time," in The Stanford Encyclopedia of Philosophy, substantive revision June 12, 2026, https://plato.stanford.edu/entries/time-thermo/.
[^46]: Judea Pearl, Causality: Models, Reasoning, and Inference, 2nd ed. (Cambridge: Cambridge University Press, 2009), https://doi.org/10.1017/CBO9780511803161.
[^47]: James Woodward, Making Things Happen: A Theory of Causal Explanation (Oxford: Oxford University Press, 2003), https://doi.org/10.1093/0195155270.001.0001.
[^48]: Callender, "Thermodynamic Asymmetry in Time."
References
Works of the SAE system cited here are archived on Zenodo, with the Chinese and English versions in the same record. The DOIs cited are concept DOIs, which always resolve to the latest version, so version numbers and access dates are not given. All are single-authored (Han Qin). Drafting and review assistance is described in the Acknowledgments.
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