Open Future

Let’s return for a moment to the question at the end of this post. I asked, “What happens if the future is indeterminate? Would not the eternalist position necessarily differ from the presentist one, in that case?”

Why necessarily different? The argument in that post was that eternalism and presentism are different descriptions of the same thing, and that we see the sameness by noting the sameness of relations between the elements of the description. But if the future is open, as Aristotle supposed, it is hard to see how we can maintain this. Aristotle says that the present is open to either having the sea battle tomorrow or not having it. With an eternalist view, the sea battle is “already there” or it is not. So in Aristotle’s view, the present has an open relationship to both possibilities. But the eternalist view seems to be truly open only to the possibility that will actually happen. We no longer have the same set of relationships.

Notice the problem. When I attempted to equate eternalism and presentism, I implicitly assumed that determinism is true. There were only three states of the universe, beginning, middle, and end. If determinism is false, things are different. There might be beginning, middle, and two potential ends. Perhaps there is a sea battle in one of the potential ends, and no sea battle in the other.

This suggests a solution to our conundrum, however. Even the presentist description in that post was inconsistent with an open future. If there is only one possible end, the future is not open, even if we insist that the unique possible end “currently doesn’t exist.” The problem then was not eternalism as such, but the fact that we started out with a determinist description of the universe. This strongly suggests that if my argument about eternalism and presentism was correct, we should be able to formulate eternalist and presentist descriptions of an open future which will be equivalent. But both will need to be different from the fixed “beginning-middle-end” described in that post.

We can simply take Aristotle’s account as the account of presentism with an open future. How can we give an eternalist account of the same thing? The basic requirement will be that the relationship between the present and the future needs to be the same in both accounts. Now in Aristotle’s account, the present has the same relationship to two different possibilities: both of them are equally possible. So to get a corresponding eternalist account, we need the present to be equally related to two futures that correspond to the two possiblities in the presentist account. I do not say “two possible futures,” but “two futures,” precisely because the account is eternalist.

The careful reader will already understand the account from the above, but let us be more explicit. The eternalist account that corresponds to the presentist account with an open future has multiple timelines, all of which “exist”, in the eternalist sense. The reader will no doubt be familiar with the idea of multiple timelines, at least from time travel fiction. In a similar way, the eternalist reworking of Aristotle’s position is that there is a timeline where the sea battle takes place, and another timeline where the sea battle does not take place. In this view, both of them “actually” happen. But even in this view, an observer in the middle location will have to say, “I do not, and cannot, know whether the sea battle will take place or not,” just as in Aristotle’s view. For the observer cannot traverse both timelines at once. From his point of view, he will take only one, but since his relationship to the two possibilities (or actualities) is the same, it is indeterminate which one it will be.

Even if one cannot prove my account of equivalence to be wrong, the reader may worry. Time travel fiction frequently seems incoherent, and this suggests that any view with multiple timelines may also be incoherent. But this potential incoherence supports the equivalence, rather than subtracting from it. For as we noted in the post on Aristotle, there is a definite appearance of incoherence in his position. It is not even clear how his view is logically possible. So it would not be surprising, but quite natural, if views which are intended to be equivalent to his position are also not clearly coherent. Nonetheless, the multiple timelines description does have some logical advantage over Aristotle’s position, in the sense that “the sea battle will take place in timeline A” does not even appear to contradict “the sea battle will not take place in timeline B.”

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Aristotle on Future Contingents

In Chapter 9 of On Interpretation, Aristotle argues that at least some statements about the future need to be exempted from the principle of Excluded Middle:

In the case of that which is or which has taken place, propositions, whether positive or negative, must be true or false. Again, in the case of a pair of contradictories, either when the subject is universal and the propositions are of a universal character, or when it is individual, as has been said,’ one of the two must be true and the other false; whereas when the subject is universal, but the propositions are not of a universal character, there is no such necessity. We have discussed this type also in a previous chapter.

When the subject, however, is individual, and that which is predicated of it relates to the future, the case is altered. For if all propositions whether positive or negative are either true or false, then any given predicate must either belong to the subject or not, so that if one man affirms that an event of a given character will take place and another denies it, it is plain that the statement of the one will correspond with reality and that of the other will not. For the predicate cannot both belong and not belong to the subject at one and the same time with regard to the future.

Thus, if it is true to say that a thing is white, it must necessarily be white; if the reverse proposition is true, it will of necessity not be white. Again, if it is white, the proposition stating that it is white was true; if it is not white, the proposition to the opposite effect was true. And if it is not white, the man who states that it is making a false statement; and if the man who states that it is white is making a false statement, it follows that it is not white. It may therefore be argued that it is necessary that affirmations or denials must be either true or false.

Now if this be so, nothing is or takes place fortuitously, either in the present or in the future, and there are no real alternatives; everything takes place of necessity and is fixed. For either he that affirms that it will take place or he that denies this is in correspondence with fact, whereas if things did not take place of necessity, an event might just as easily not happen as happen; for the meaning of the word ‘fortuitous’ with regard to present or future events is that reality is so constituted that it may issue in either of two opposite directions. Again, if a thing is white now, it was true before to say that it would be white, so that of anything that has taken place it was always true to say ‘it is’ or ‘it will be’. But if it was always true to say that a thing is or will be, it is not possible that it should not be or not be about to be, and when a thing cannot not come to be, it is impossible that it should not come to be, and when it is impossible that it should not come to be, it must come to be. All, then, that is about to be must of necessity take place. It results from this that nothing is uncertain or fortuitous, for if it were fortuitous it would not be necessary.

The argument here is that if it is already true, for example, that I will eat breakfast tomorrow, then I will necessarily eat breakfast tomorrow, and there is no option about this and no ability of anything to prevent it. Aristotle is here taking it for granted that some things about the future are uncertain, and is using this as a reductio against the position that such claims can be already true. He goes on to give additional reasons for the same thing:

Again, to say that neither the affirmation nor the denial is true, maintaining, let us say, that an event neither will take place nor will not take place, is to take up a position impossible to defend. In the first place, though facts should prove the one proposition false, the opposite would still be untrue. Secondly, if it was true to say that a thing was both white and large, both these qualities must necessarily belong to it; and if they will belong to it the next day, they must necessarily belong to it the next day. But if an event is neither to take place nor not to take place the next day, the element of chance will be eliminated. For example, it would be necessary that a sea-fight should neither take place nor fail to take place on the next day.

These awkward results and others of the same kind follow, if it is an irrefragable law that of every pair of contradictory propositions, whether they have regard to universals and are stated as universally applicable, or whether they have regard to individuals, one must be true and the other false, and that there are no real alternatives, but that all that is or takes place is the outcome of necessity. There would be no need to deliberate or to take trouble, on the supposition that if we should adopt a certain course, a certain result would follow, while, if we did not, the result would not follow. For a man may predict an event ten thousand years beforehand, and another may predict the reverse; that which was truly predicted at the moment in the past will of necessity take place in the fullness of time.

Further, it makes no difference whether people have or have not actually made the contradictory statements. For it is manifest that the circumstances are not influenced by the fact of an affirmation or denial on the part of anyone. For events will not take place or fail to take place because it was stated that they would or would not take place, nor is this any more the case if the prediction dates back ten thousand years or any other space of time. Wherefore, if through all time the nature of things was so constituted that a prediction about an event was true, then through all time it was necessary that that should find fulfillment; and with regard to all events, circumstances have always been such that their occurrence is a matter of necessity. For that of which someone has said truly that it will be, cannot fail to take place; and of that which takes place, it was always true to say that it would be.

Yet this view leads to an impossible conclusion; for we see that both deliberation and action are causative with regard to the future, and that, to speak more generally, in those things which are not continuously actual there is potentiality in either direction. Such things may either be or not be; events also therefore may either take place or not take place. There are many obvious instances of this. It is possible that this coat may be cut in half, and yet it may not be cut in half, but wear out first. In the same way, it is possible that it should not be cut in half; unless this were so, it would not be possible that it should wear out first. So it is therefore with all other events which possess this kind of potentiality. It is therefore plain that it is not of necessity that everything is or takes place; but in some instances there are real alternatives, in which case the affirmation is no more true and no more false than the denial; while some exhibit a predisposition and general tendency in one direction or the other, and yet can issue in the opposite direction by exception.

Now that which is must needs be when it is, and that which is not must needs not be when it is not. Yet it cannot be said without qualification that all existence and non-existence is the outcome of necessity. For there is a difference between saying that that which is, when it is, must needs be, and simply saying that all that is must needs be, and similarly in the case of that which is not. In the case, also, of two contradictory propositions this holds good. Everything must either be or not be, whether in the present or in the future, but it is not always possible to distinguish and state determinately which of these alternatives must necessarily come about.

Let me illustrate. A sea-fight must either take place to-morrow or not, but it is not necessary that it should take place to-morrow, neither is it necessary that it should not take place, yet it is necessary that it either should or should not take place to-morrow. Since propositions correspond with facts, it is evident that when in future events there is a real alternative, and a potentiality in contrary directions, the corresponding affirmation and denial have the same character.

This is the case with regard to that which is not always existent or not always nonexistent. One of the two propositions in such instances must be true and the other false, but we cannot say determinately that this or that is false, but must leave the alternative undecided. One may indeed be more likely to be true than the other, but it cannot be either actually true or actually false. It is therefore plain that it is not necessary that of an affirmation and a denial one should be true and the other false. For in the case of that which exists potentially, but not actually, the rule which applies to that which exists actually does not hold good. The case is rather as we have indicated.

Basically, then, there are two arguments. First there is the argument that if statements about the future are already true, the future is necessary. If a sea battle will take place tomorrow, it will necessarily take place. Second, there is the argument that this excludes deliberation. If a sea battle will take place tomorrow, then it will necessarily take place, and no place remains for deliberation and decision about whether to fight the sea battle. Whether you decide to fight or not, it will necessarily take place.

Unfortunately for Aristotle, both arguments fail. Consider the first argument about necessity. Aristotle’s example is that “if it is true to say that a thing is white, it must necessarily be white.” But this is hypothetical necessity, not absolute necessity. A thing must be white if it is true that is white, but that does not mean that “it must be white, period.” Thus for example I have a handkerchief, and it happens to be white. If it is true that it is white, then it must be white. But it would be false to simply say, “My handkerchief is necessarily white.” Since I can dye it other colors, obviously it is not simply necessary for it to be white.

In a similar way, of course it is true that if a sea battle will take place, it will take place. It does not follow at all that “it will necessarily take place, period.”

Again, consider the second argument, that deliberation would be unnecessary. Aristotle makes the point that deliberation is causative with respect to the future. But gravity is also causative with respect to the future, as for example when gravity causes a cup to fall from a desk. It does not follow either that the cup must be able not to fall, nor that gravity is unnecessary. In a similar way, a sea battle takes place because certain people deliberated and decided to fight. If it was already true that it was going to take place, then it also already true that they were going to decide to fight. It does not follow that their decision was unnecessary.

Consider the application to gravity. It is already true that if the cup is knocked from the desk, it will fall. It does not follow that gravity will not cause the fall: in fact, it is true precisely because gravity will cause the fall. In a similar way, if it true that the battle will take place, it is true because the decision will be made.

This earlier discussion about determinism is relevant to this point. Asserting that there is a definite outcome that our deliberations will arrive at, in each case, goes against our experience in no way. The feeling of “free will,” in any case, has a different explanation, whether or not determinism is true.

On the other hand, there is also no proof that there is such a determinate outcome, even if in some cases there are things that would suggest it. What happens if in fact there is nothing ensuring one outcome rather than another?

Here we could make a third argument on Aristotle’s behalf, although he did not make it himself. If the present is truly open to alternative outcomes, then it seems that nothing exists that could make it be true that “a sea battle will take place,” and false that “a sea battle will not take place.” Presumably if a statement is true, there must be something in reality which is the cause of the statement’s truth. Now there does not seem to be anything in reality, in this scenario, which could be a cause of truth. Therefore it does not seem that either alternative could be true, and Aristotle would seem to be right.

I will not attempt to refute this argument at this point, but I will raise two difficulties. First of all, it is not clear that his claim is even coherent. Aristotle says that “either there will be a sea battle or there will not be,” is true, but that “there will be a sea battle” is not true, and “there will not be a sea battle” is not true. This does not seem to be logically consistent, and it is not clear that we can even understand what is being said. I will not push this objection too hard, however, lest I be accused of throwing stones from a glass house.

Second, the argument that there is nothing in reality that could cause the truth of a statement might apply to the past as well as to the future. There is a tree outside my window right now. What was in that place exactly 100 million years ago to this moment? It is not obvious that there is anything in the present world which could be the cause of the truth of any statement about this. One might object that the past is far more determinate than the future. There are plenty of things in the present world that might be the cause of the truth of the statement, “World War II actually happened.” It is hard to see how you could possibly have arrived at the present world without it, and this “necessity” of World War II in order to arrive at the present world could be the cause of truth. The problem is that there is still no proof that this is universal. Once things are far enough in past, like 100 million years, perhaps minor details become indeterminate. Will Aristotle really want to conclude that some statements about the past are neither true nor false?

I will more or less leave things here without resolving them in this post, although I will give a hint (without proof at this time) regarding the truth of the matter. It turns out that quantum mechanics can be interpreted in two ways. In one way, it is a deterministic theory, and in this way it is basically time reversible. The present fully determines the past, but it equally fully determines the future. Interpreted in another way, it is an indeterministic theory which leaves the future uncertain. But understood in this way, it also leaves the past uncertain.

Really and Truly True

There are two persons in a room with a table between them. One says, “There is a table on the right.” The other says, “There is a table on the left.”

Which person is right? The obvious answer is that both are right. But suppose they attempt to make this into a metaphysical disagreement.

“Yes, in a relative sense, the table is on the right of one of us and on the left of the other. But really and truly, at a fundamental level, the table is on the right, and not on the left.”

“I agree that there must be a fundamental truth to where the table is. But I think it is really and truly on the left, and not on the right.”

Now both are wrong, because it is impossible for the relationships of “on the right” and “on the left” to exist without correlatives, and the assertion that the table is “really and truly” on the right or on the left means nothing here except that these things do not depend on a relationship to an observer.

Thus both people are right, if they intend their assertions in a common sense way, and both are wrong, if they intend their assertions in the supposed metaphysical way. Could it happen that one is right and the other wrong? Yes, if one intends to speak in the common sense way, and the other in the metaphysical way, but not if they are speaking in the same way.

In the Mathematical Principles of Natural Philosophy, Newton explains his ideas of space and time:

I. Absolute, true, and mathematical time, of itself, and from its own nature flows equably without regard to anything external, and by another name is called duration: relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time; such as an hour, a day, a month, a year.

II. Absolute space, in its own nature, without regard to anything external, remains always similar and immovable. Relative space is some movable dimension or measure of the absolute spaces; which our senses determine by its position to bodies; and which is vulgarly taken for immovable space; such is the dimension of a subterraneous, an æreal, or celestial space, determined by its position in respect of the earth. Absolute and relative space, are the same in figure and magnitude; but they do not remain always numerically the same. For if the earth, for instance, moves, a space of our air, which relatively and in respect of the earth remains always the same, will at one time be one part of the absolute space into which the air passes; at another time it will be another part of the same, and so, absolutely understood, it will be perpetually mutable.

III. Place is a part of space which a body takes up, and is according to the space, either absolute or relative. I say, a part of space; not the situation, nor the external surface of the body. For the places of equal solids are always equal; but their superfices, by reason of their dissimilar figures, are often unequal. Positions properly have no quantity, nor are they so much the places themselves, as the properties of places. The motion of the whole is the same thing with the sum of the motions of the parts; that is, the translation of the whole, out of its place, is the same thing with the sum of the translations of the parts out of their places; and therefore the place of the whole is the same thing with the sum of the places of the parts, and for that reason, it is internal, and in the whole body.

IV. Absolute motion is the translation of a body from one absolute place into another; and relative motion, the translation from one relative place into another. Thus in a ship under sail, the relative place of a body is that part of the ship which the body possesses; or that part of its cavity which the body fills, and which therefore moves together with the ship: and relative rest is the continuance of the body in the same part of the ship, or of its cavity. But real, absolute rest, is the continuance of the body in the same part of that immovable space, in which the ship itself, its cavity, and all that it contains, is moved. Wherefore, if the earth is really at rest, the body, which relatively rests in the ship, will really and absolutely move with the same velocity which the ship has on the earth. But if the earth also moves, the true and absolute motion of the body will arise, partly from the true motion of the earth, in immovable space; partly from the relative motion of the ship on the earth; and if the body moves also relatively in the ship; its true motion will arise, partly from the true motion of the earth, in immovable space, and partly from the relative motions as well of the ship on the earth, as of the body in the ship; and from these relative motions will arise the relative motion of the body on the earth. As if that part of the earth, where the ship is, was truly moved toward the east, with a velocity of 10010 parts; while the ship itself, with a fresh gale, and full sails, is carried towards the west, with a velocity expressed by 10 of those parts; but a sailor walks in the ship towards the east, with 1 part of the said velocity; then the sailor will be moved truly in immovable space towards the east, with a velocity of 10001 parts, and relatively on the earth towards the west, with a velocity of 9 of those parts.

While the details of Einstein’s theory of relativity may have been contingent, it is not difficult to see that Newton’s theory here is mistaken, and that anyone could have known it at the time. It is mistaken in precisely the way the people described above are mistaken in saying that the table is “really and truly” on the left or on the right.

For example, suppose the world had a beginning in time. Does it make sense to ask whether it could have started at a later time, or at an earlier one? It does not, because “later” and “earlier” are just as relative as “on the left” and “on the right,” and there is nothing besides the world in relation to which the world could have these relations. Could all bodies have been shifted a bit in one direction or another? No. This has no meaning, just as it has no meaning to be on the right without being on the right of something or other.

In an amusing exchange some years ago between Vladimir Nesov and Eliezer Yudkowsky, Nesov says:

Existence is relative: there is a fact of the matter (or rather: procedure to find out) about which things exist where relative to me, for example in the same room, or in the same world, but this concept breaks down when you ask about “absolute” existence. Absolute existence is inconsistent, as everything goes. Relative existence of yourself is a trivial question with a trivial answer.

Yudkowsky responds:

Absolute existence is inconsistent

Wha?

Yudkowsky is taken aback by the seemingly nonchalant affirmation of an apparently abstruse metaphysical claim, which if not nonsensical would appear to be the absurd claim that existence is impossible.

But Nesov is quite right: to exist is to exist in relation to other things. Thus to exist “absolutely” would be like “being absolutely on the right,” which is impossible.

Suppose we confront our original disputants with the fact that right and left are relative terms, and there is no “really true truth” about the relative position of the table. It is both on the right and on the left, relative to the disputants, and apart from these relationships, it is neither.

“Ok,” one responds, “but there is still a deep truth about where the table is: it is here in this room.”

“Actually,” the other answers, “The real truth is that it is in the house.”

Once again, both are right, if these are taken as common sense claims, and both are wrong, if this is intended to be a metaphysical dispute where one would be true, the real truth about where the table is, and the other would be false.

Newton’s idea of absolute space is an extension of this argument: “Ok, then, but there is still a really true truth about where the table is: it is here in absolute space.” But obviously this is just as wrong as all the other attempts to find out where the table “really” is. The basic problem is that “where is this” demands a relative response. It is a question about relationships in the first place. We can see this in fact even in Newton’s account: it is here in absolute space, that is, it is close to certain areas of absolute space and distant from certain other areas of absolute space.

Something similar will be true about existence to the degree that existence is also implicitly relative. “Where is this thing in the nature of things?” also requires a relative response: what relationship does this have to the rest of the order of reality? And in a similar way, questions about what is “really and truly true,” if taken to imply an abstraction from this relative order, will not have any answer. In a previous post, I said something like this in relation to the question, “how many things are here?” Reductionists and anti-reductionists disputing about whether a large object is “really and truly a cloud of particles” or “really and truly a single object,” are in exactly the same position as the disputants about the position of the table: both claims are true, in a common sense way, and both claims are false, if taken in a mutually exclusive metaphysical sense, since speaking of one or many is already to involve the perspective of the knower, in particular as knowing division and its negation.

Of course, an anti-reductionist has some advantage here because they can respond, “Actually, no one in a normal context would ever call a large object a cloud of particles. So it is not common sense at all.” This is true as far as it goes, but it is not really to the point, since no one denies in a common sense context that large objects also consist of many things, as a person has a head, legs, and arms, and a chair has legs and a back. It is not that the “cloud of particles” account is so much incorrect as it is adopting a very unusual perspective. Thus someone on the moon might say that the table is 240,000 miles away, which is a very unusual thing to say of a table, compared to saying that it is on the left or on the right.

None of this is unique to the question of “how many.” Since there is an irreducible element of relativity in being itself, we will be able to find some application to every question about the being of things.

Predictive Processing

In a sort of curious coincidence, a few days after I published my last few posts, Scott Alexander posted a book review of Andy Clark’s book Surfing Uncertainty. A major theme of my posts was that in a certain sense, a decision consists in the expectation of performing the action decided upon. In a similar way, Andy Clark claims that the human brain does something very similar from moment to moment. Thus he begins chapter 4 of his book:

To surf the waves of sensory stimulation, predicting the present is simply not enough. Instead, we are built to engage the world. We are built to act in ways that are sensitive to the contingencies of the past, and that actively bring forth the futures that we need and desire. How does a guessing engine (a hierarchical prediction machine) turn prediction into accomplishment? The answer that we shall explore is: by predicting the shape of its own motor trajectories. In accounting for action, we thus move from predicting the rolling present to predicting the near-future, in the form of the not-yet-actual trajectories of our own limbs and bodies. These trajectories, predictive processing suggests, are specified by their distinctive sensory (especially proprioceptive) consequences. In ways that we are about to explore, predicting these (non-actual) sensory states actually serves to bring them about.

Such predictions act as self-fulfilling prophecies. Expecting the flow of sensation that would result were you to move your body so as to keep the surfboard in that rolling sweet spot results (if you happen to be an expert surfer) in that very flow, locating the surfboard right where you want it. Expert prediction of the world (here, the dynamic ever-changing waves) combines with expert prediction of the sensory flow that would, in that context, characterize the desired action, so as to bring that action about.

There is a great deal that could be said about the book, and about this theory, but for the moment I will content myself with remarking on one of Scott Alexander’s complaints about the book, and making one additional point. In his review, Scott remarks:

In particular, he’s obsessed with showing how “embodied” everything is all the time. This gets kind of awkward, since the predictive processing model isn’t really a natural match for embodiment theory, and describes a brain which is pretty embodied in some ways but not-so-embodied in others. If you want a hundred pages of apologia along the lines of “this may not look embodied, but if you squint you’ll see how super-duper embodied it really is!”, this is your book.

I did not find Clark obsessed with this, and I think it would be hard to reasonably describe any hundred pages in the book as devoted to this particular topic. This inclines to me to suggest that Scott may be irritated by such discussion of the topic that comes up because it does not seem relevant to him. I will therefore explain the relevance, namely in relation to a different difficulty which Scott discusses in another post:

There’s something more interesting in Section 7.10 of Surfing Uncertainty [actually 8.10], “Escape From The Darkened Room”. It asks: if the brain works to minimize prediction error, isn’t its best strategy to sit in a dark room and do nothing forever? After all, then it can predict its sense-data pretty much perfectly – it’ll always just stay “darkened room”.

Section 7.10 [8.10] gives a kind of hand-wave-y answer here, saying that of course organisms have some drives, and probably it makes sense for them to desire novelty and explore new options, and so on. Overall this isn’t too different from PCT’s idea of “intrinsic error”, and as long as we remember that it’s not really predicting anything in particular it seems like a fair response.

Clark’s response may be somewhat “hand-wave-y,” but I think the response might seem slightly more problematic to Scott than it actually is, precisely because he does not understand the idea of embodiment, and how it applies to this situation.

If we think about predictions on a general intellectual level, there is a good reason not to predict that you will not eat something soon. If you do predict this, you will turn out to be wrong, as is often discovered by would-be adopters of extreme fasts or diets. You will in fact eat something soon, regardless of what you think about this; so if you want the truth, you should believe that you will eat something soon.

The “darkened room” problem, however, is not about this general level. The argument is that if the brain is predicting its actions from moment to moment on a subconscious level, then if its main concern is getting accurate predictions, it could just predict an absence of action, and carry this out, and its predictions would be accurate. So why does this not happen? Clark gives his “hand-wave-y” answer:

Prediction-error-based neural processing is, we have seen, part of a potent recipe for multi-scale self-organization. Such multiscale self-organization does not occur in a vacuum. Instead, it operates only against the backdrop of an evolved organismic (neural and gross-bodily) form, and (as we will see in chapter 9) an equally transformative backdrop of slowly accumulated material structure and cultural practices: the socio-technological legacy of generation upon generation of human learning and experience.

To start to bring this larger picture into focus, the first point to notice is that explicit, fast timescale processes of prediction error minimization must answer to the needs and projects of evolved, embodied, and environmentally embedded agents. The very existence of such agents (see Friston, 2011b, 2012c) thus already implies a huge range of structurally implicit creature-specific ‘expectations’. Such creatures are built to seek mates, to avoid hunger and thirst, and to engage (even when not hungry and thirsty) in the kinds of sporadic environmental exploration that will help prepare them for unexpected environmental shifts, resource scarcities, new competitors, and so on. On a moment-by-moment basis, then, prediction error is minimized only against the backdrop of this complex set of creature-defining ‘expectations’.”

In one way, the answer here is a historical one. If you simply ask the abstract question, “would it minimize prediction error to predict doing nothing, and then to do nothing,” perhaps it would. But evolution could not bring such a creature into existence, while it was able to produce a creature that would predict that it would engage the world in various ways, and then would proceed to engage the world in those ways.

The objection, of course, would not be that the creature of the “darkened room” is possible. The objection would be that since such a creature is not possible, it must be wrong to describe the brain as minimizing prediction error. But notice that if you predict that you will not eat, and then you do not eat, you are no more right or wrong than if you predict that you will eat, and then you do eat. Either one is possible from the standpoint of prediction, but only one is possible from the standpoint of history.

This is where being “embodied” is relevant. The brain is not an abstract algorithm which has no content except to minimize prediction error; it is a physical object which works together in physical ways with the rest of the human body to carry out specifically human actions and to live a human life.

On the largest scale of evolutionary history, there were surely organisms that were nourished and reproduced long before there was anything analagous to a mind at work in those organisms. So when mind began to be, and took over some of this process, this could only happen in such a way that it would continue the work that was already there. A “predictive engine” could only begin to be by predicting that nourishment and reproduction would continue, since any attempt to do otherwise would necessarily result either in false predictions or in death.

This response is necessarily “hand-wave-y” in the sense that I (and presumably Clark) do not understand the precise physical implementation. But it is easy to see that it was historically necessary for things to happen this way, and it is an expression of “embodiment” in the sense that “minimize prediction error” is an abstract algorithm which does not and cannot exhaust everything which is there. The objection would be, “then there must be some other algorithm instead.” But this does not follow: no abstract algorithm will exhaust a physical object. Thus for example, animals will fall because they are heavy. Asking whether falling will satisfy some abstract algorithm is not relevant. In a similar way, animals had to be physically arranged in such a way that they would usually eat and reproduce.

I said I would make one additional point, although it may well be related to the above concern. In section 4.8 Clark notes that his account does not need to consider costs and benefits, at least directly:

But the story does not stop there. For the very same strategy here applies to the notion of desired consequences and rewards at all levels. Thus we read that ‘crucially, active inference does not invoke any “desired consequences”. It rests only on experience-dependent learning and inference: experience induces prior expectations, which guide perceptual inference and action’ (Friston, Mattout, & Kilner, 2011, p. 157). Apart from a certain efflorescence of corollary discharge, in the form of downward-flowing predictions, we here seem to confront something of a desert landscape: a world in which value functions, costs, reward signals, and perhaps even desires have been replaced by complex interacting expectations that inform perception and entrain action. But we could equally say (and I think this is the better way to express the point) that the functions of rewards and cost functions are now simply absorbed into a more complex generative model. They are implicit in our sensory (especially proprioceptive) expectations and they constrain behavior by prescribing their distinctive sensory implications.

The idea of the “desert landscape” seems to be that this account appears to do away with the idea of the good, and the idea of desire. The brain predicts what it is going to do, and those predictions cause it to do those things. This all seems purely intellectual: it seems that there is no purpose or goal or good involved.

The correct response to this, I think, is connected to what I have said elsewhere about desire and good. I noted there that we recognize our desires as desires for particular things by noticing that when we have certain feelings, we tend to do certain things. If we did not do those things, we would never conclude that those feelings are desires for doing those things. Note that someone could raise a similar objection here: if this is true, then are not desire and good mere words? We feel certain feelings, and do certain things, and that is all there is to be said. Where is good or purpose here?

The truth here is that good and being are convertible. The objection (to my definition and to Clark’s account) is not a reasonable objection at all: it would be a reasonable objection only if we expected good to be something different from being, in which case it would of course be nothing at all.

Knowing Knowing and Known

In his work On the Soul, Aristotle points out that knowledge of powers depends on the knowledge of activities, and knowledge of activities depends on knowledge of the objects of the activities:

It is necessary for the student of these forms of soul first to find a definition of each, expressive of what it is, and then to investigate its derivative properties, &c. But if we are to express what each is, viz. what the thinking power is, or the perceptive, or the nutritive, we must go farther back and first give an account of thinking or perceiving, for in the order of investigation the question of what an agent does precedes the question, what enables it to do what it does. If this is correct, we must on the same ground go yet another step farther back and have some clear view of the objects of each; thus we must start with these objects, e.g. with food, with what is perceptible, or with what is intelligible.

A little thought will establish that this is entirely necessary. In order to have a general knowledge of the power or the activity, however, it will be sufficient to have a general knowledge of the object. But given that human knowledge proceeds from the general to the specific, it would be reasonable to believe that a detailed knowledge of the power or activity might require a somewhat equally detailed knowledge of the object.

We can see how this would happen by thinking about the example of eating and food. A general idea of both eating and food might be this: eating is taking in other bodies and using them for growth and for energy for other living activities, and food is what can be taken in and used in this way.

Both the idea of eating and the idea of food here are fairly general, and due to their generality they leave open various questions. For example, why is not possible to live off air? Air is a body, and in physics it is in some sense convertible with energy, so it would not seem unreasonable if it could provide the matter and energy that we need in order to grow and to live in other ways.

The general account does not of course assert that this is a possibility, but neither does it deny the possibility. So if someone thinks that the general account tells them all that needs to be known about eating and food, they will not be unlikely to conclude that living off air should be a possibility. If someone drew this conclusion it would be an example of impatience with respect to truth. The example is not very realistic, of course, even if there are a few people who actually draw this conclusion, but this lack of realism is not because of some flaw in the idea of the knowledge of activities depending on the knowledge of objects, but just because most people already accept that air is not a kind of food, even if they do not know why it is not. So they already have a somewhat more detailed knowledge of the object, and therefore also of the activity.

Something similar will result with other powers of the soul, and with powers in general. In the case of knowledge in particular, a general knowledge of knowing will depend on a general knowledge of the known or knowable, and a detailed knowledge of knowing will depend on a detailed knowledge of the known or knowable. And just as in the example above, a general knowledge does not necessarily lead someone into error, but it can leave open questions, and one who is impatient for truth might draw detailed conclusions too soon. In this case, a likely result would be that someone confuses the mode of knowledge and the mode of the known, although this would not be the only way to fall into error.

Sean Collins discusses the history of science and its relationship with philosophy:

In my post of March 6, I noted that we must distinguish between what science has been and what it ought to be, or what it is naturally ordained to be. It is therefore a mistake to take any current or past state of science and construe that as universal without any argument. It is a mistake, for example, to suppose that the Galilean paradigm of physics as “written in mathematical terms” is a universal truth, merely on the ground that physics has been that way for some time, and indeed with some fair degree of success. Or, again, I shall argue, it is a mistake to infer that science consists essentially, and by its permanent universal nature, in reasoning from artificial “paradigms,” even if the recent history of science suggests that.

But from this one might be inclined to draw either of two diametrically opposite inferences. One would be to suppose that history and science have nothing to do with each other, otherwise than accidentally. We should therefore try to find out what science is really supposed to be, and let it be that. But the opposite conclusion seems perhaps equally justifiable: namely that science is essentially historical, so that stages in its progress are precisely stages, and therefore ought not to be confused with the universal character of science itself.

Which is the right conclusion? Should we think that science and history have any real connection? To make the question suitably concrete, we should first recognize that this is really a question about humanity. It is humanity we are wondering about when we ask whether our knowledge has any essential relation with history. It is about the being called “man” himself that we must finally ask whether there is something essentially historical.

But then we can see, perhaps, that this is no small question, and it would scarcely do it justice to propose an answer to it in a few short paragraphs. For now, I will let it suffice to have asked the question. But I would also like to take note of some significant historical facts which suggest a direction in which to seek an answer. And after that I will propose what I think is an absolutely fundamental and critical principle on the way to finding an answer.

The signs I have in mind are these. Some 2500 years ago, Aristotle wrote his Organon, which laid out the delineations of “science.” Aristotle argued that science, in the strictest sense, must be knowledge from universal causes, that these causes must be expressed in self-evident principles, and that the principles must derive from the essences of things as expressed in their definitions. Historically, that view seemed to hold a very firm sway for a very long time, until something strange happened: there was a revolt. Francis Bacon, Galileo, and Descartes were primary agents of the revolt. The revolt was in large measure a backlash against entrenched stagnation, against which irrepressible spirits finally grew indignant. From that moment on, intellectual culture became bifurcated into “science” and “philosophy,” and that bifurcation remains to this day.

Those who remain in the camp of the “philosophers” often stake their claims on the basis of the original claims of Aristotle’s Posterior Analytics. They resist the intrusions of science on the alleged ground that only philosophy proceeds in a truly universal mode, seeking definitions by “genus and difference,” aiming at truly universal causes, and proposing its theses with complete certitude. Those, on the other hand, who decide to be “scientists” stake their claims on the basis of what they take to be reality itself. They notice the truly astonishing degree to which physical reality has a structure, a structure which reaches down deeply into the materiality of things. They see, all too well, that the discovery and appreciation of that structure absolutely demands a mode of thought which is not that of conventional philosophy. And they cannot, moreover, help but notice that conventional philosophers have often tended to either be completely ignorant of that structure, or worse yet, to not care about it, or to deny that it matters, or to deny that it really exists at all.

To describe this by a succinct approximation, we might say that the philosophical mindset tries to reason from characteristics of the mind: from its yearning for what transcends the murkiness of matter. The scientific mindset, by contrast, seeks to reason from the characteristics of physical reality, even possibly at the expense of the aspirations of human reason towards what is immaterial.

While one might agree that it does not “do justice” to the question in the sense of discussing it adequately, we can see from what has been said that one cannot fully separate science from history. If we ask, “what is the nature of science,” we are asking about the nature of human knowing. In order to answer this, we require knowledge of knowing. But since knowing knowing in a detailed way depends on knowing the known in a detailed way, the question of whether history is essentially involved in knowing knowing depends on whether knowing the known in a detailed way is an essentially historical process.

Human beings and especially the life of an individual human being are very small parts of reality. One consequence is that the single lifetime of an individual is not enough to come to a detailed knowledge of the physical world without an essential dependence on the work of others, which dependence implies a historical process. The “astonishing degree to which physical reality has a structure” is something that necessarily takes many human lifetimes to come to know, and is the collective work of the human race, not the work of an individual.

Speaking of Aristotle’s attitude towards matter in science, Collins says:

Aristotle, as I have noted, saw that materiality is a true principle of natural being. Henceforth, it was no longer necessary to shun matter, as the Platonists had, as if it were repugnant to philosophical endeavors. One could reason about the natural, physical world, and one could reason about it as physical.

Yet we are — no doubt inevitably — slow to grasp the implications of materiality. Even about this very historical fact, many of us tend to think in a quasi-Platonic way. And what I am about to assert will no doubt astonish some readers: even Aristotle himself continued to think in a somewhat Platonic way, despite his recognition of the principle of materiality. But anyone who is acquainted with the history of thought shouldn’t be entirely surprised at my assertion. It is common — ordinary, in fact — for great thinkers, who find themselves at the dawn of a new and fuller vision of the order of things, to have one foot remaining in the older vision, not entirely able to see the implications of their own new intuitions. If one assumes that thought ought to evolve, as opposed to merely changing in revolutionary fits, one should find this even perhaps a little reassuring.

So what do I mean when I say that Aristotle thinks in a semi-Platonic way? Briefly, I mean that, even despite himself in a way, he continues to seek the accounts, the logoi, of things in a way that would place them more in the order of the purely intellectual than the physical. For example, he seeks to understand what time is in a way that makes virtually no appeal to such physical evidence as we have nowadays through physical experimentation. (Of course! How could he make appeal to something that didn’t exist yet?) He supposes, rather inevitably, that simply thinking about time and motion from the relatively deficient point of view of something called  “common experience” will give him something like a sufficient account of what he is trying to understand. And in the end, his vision of an eternal first motion as the source of time, a motion perfectly circular and unchanging, deriving from the causality of a First Mover who could not directly be the source of any contingent effects — this is a vision which now, from the point of view of contemporary science as well as Christian theology, rightly strikes us as not yet a mature vision in its understanding of the role of matter in the order of the cosmos.

This, to be sure, is not a criticism of Aristotle, as if to suggest that he should have thought something else; rather, it is merely an observation of how human thought inevitably takes time to  develop. Nor do I mean to suggest that what Aristotle saw was of negligible account. It belongs precisely to what I am calling the order of concretion to begin with the relatively abstract in our understanding of material things, and this is because matter is ordered to form more than vice versa. This can be illustrated in the design of artifacts, for in them also there is always a material and a formal element. Thus, for example, barring special circumstances, one does not ordinarily design a building by first looking at what materials to use; rather one considers what form and function they are to serve, and then one chooses materials accordingly. Though there are circumstantial exceptions to this principle, it remains a principle; and it is clear enough that a systematic disregard of it would make our thought chaotic.

Thus one can see that there is a philosophical justification for doing what Aristotle did. We might describe this justification in another way as well: it derives from the fact that the human mind must bear some proportion to the reality it is to know. For having understood something of the difference between the order of intellect and the order of physical being, we still suppose, rightly, that there must be a proportion between them. Yet this rather abstract statement leaves much in doubt. How is the human mind to fulfill its destiny to know physical reality? I shall trust my readers to be able to understand that the answer to that question could not look the same in the 4th century BC as it looks now….

It is possible that Collins is too generous to Aristotle here, perhaps for the sake of his readers and for the sake of his own intellectual tradition, in the sense that to some extent, it seems likely that some of Aristotle’s conclusions are “impatient” in the way we have discussed earlier. Nonetheless his basic assertion is correct. Knowing the nature of knowledge in detail requires more knowledge of the knowable thing than Aristotle could have had at the time. As Collins says, this is “merely an observation of how human thought inevitably takes time to develop.” And even if there is some intellectual impatience there, there is perhaps no more such impatience than is generally found in those who seek to understand reality.

 

Irreversible Change

Many plans for human society may be possible in the way that bringing back last Friday is impossible, and yet not be real human possibilities. It is easy for us to see this in the case of plans that correspond to things that have never existed, as for example the sort of plan proposed by people with socialist tendencies. For example, the Tradinista manifesto states:

8. Livelihood should not depend on the market.

Markets are not unjust in themselves, but they become vehicles of exploitation when people must sell their labor-power on the market in order to survive. So, while citizens should be free to engage in market exchange, the polity should ensure that no basic needs – food, clothing, shelter, healthcare, etc. – go unmet, guaranteeing a livelihood independent of the market.

Consider this as it stands. According to this, markets are “vehicles of exploitation” if I have no way to survive without selling my labor-power, that is, without getting a job. “The polity should ensure” that this does not happen. It must guarantee that if I prefer not to get a job, I do not need to get one, and that there remains a way for me to survive without one.

Let’s suppose we live in such a polity, and I declare that I don’t like jobs, and I have decided that I will not get one. What happens now? How does the polity ensure that I can survive, and that I do not need to get a job?

The tradinista response becomes somewhat confused when confronted directly with this question. They do not clearly state that they favor a Basic Income guarantee, but in fact this would be the only reasonable way to implement their requirement without making people who choose not to work into slaves, which would thereby nullify the idea that people are not obliged to work, as one can see after a little thought. We will look at this more closely below.

The problem with the manifesto is not that it favors a basic income. It might well turn out that the idea is reasonable, and that someday it can be implemented in some society. But there is indeed a problem with the claim that this belongs to the very essence of a just society. There is simply no proof, nor good reasons to believe, that this is workable or conducive to human welfare in the real world and in presently existing societies. Suppose the USA were to adopt the above statement from the tradinista manifesto as a constitutional amendment. If they are right that this belongs to the nature of a just society, such an amendment would be commendable.

First, some people may decide to stop working. I might do so myself, given my preference for the useless. “The polity” would be obliged to support these people. Whether given as money or in other forms, that support would be taken from taxes, which would mean that taxes would rise. This might make working for a living more uncomfortable for some others, and some of these might decide to stop working themselves. And so the process might well repeat until the whole of society is at the level of bare subsistence, and many would die, as a result of their borderline subsistence condition.

Now there is no guarantee that we would get this result. But there is no guarantee that we would not, so the tradinista proposal does not make sense as a condition for a just society, unless they view this consequence as acceptable.

All of this is in fact why St. Paul says, “For even when we were with you, we gave you this command: Anyone unwilling to work should not eat.”

The tradinista site responds to this use of St. Paul:

“He who does not work, neither shall he eat.” In using this line against the Manifesto Milco puts himself in the tradition of those many who have imagined an apodictic Apostolic anathematization of Left politics; he also demonstrates how little he understands the philosophy embedded in the Manifesto.

Neither the Tradinista Collective nor any other Leftist thinkers imagine that human welfare might be decoupled from human labor. Indeed, in their relentless emphasis on the importance of the common worker, Leftists tend to emphasize just how essential work is to the maintenance and flourishing of society. Leftists do not differ from apologists of capital by devaluing labor – they differ in their view of how labor should be politically governed.

One of the basic insights of the Left, to which the Manifesto is much indebted, is that the absence or near-invisibility of explicit physical coercion does not therefore make the market an arena of authentic human freedom. The Manifesto’s authors take for granted that in labor relations, in debts, and in interactions with the agents of state power, a liberal illusion of free and equal treatment under the law often hides instances of oppression and corruption – instances which liberals can endorse only because their worldview allows them to be overlooked. Once however they are not overlooked, the formal or legal distinction of free and unfree labor becomes only one important distinction among many. To rely solely on that distinction, to “outsource” decisions about the relations of workers to the market, seems to the authors of the Manifesto to be a kind of ethical abdication – a fine illustration of the weakness of moral philosophy in our times.

This is virtually incoherent. Consider again the statement from the manifesto, that markets “become vehicles of exploitation when people must sell their labor-power on the market in order to survive.” What is the alternative? In the response above, they say in a roundabout way, although with much confusion, “yes, people will still have to work, or they won’t be able to survive.” But then either they are being paid for their work, and thus they are selling their labor, or they are not being paid. The implication of these alternatives is obvious: either you sell your labor for money, or you sell yourself into slavery. Your choice.

Chesterton’s argument is that the above sort of argument should only apply to things that have never existed, such as socialism. It should not apply to arrangements that have actually existed in the real world. Times are all alike, so if something has existed in the past, it can exist again.

The response to this is found in the last post. In many cases, neither the original arrangements nor the new arrangements came about by human planning. So we should not find it surprising if human planning cannot revert things to the original arrangement. In this sense, many changes in human society are in fact humanly irreversible.

Nothing New Under the Sun

Vanity of vanities, says the Teacher,
    vanity of vanities! All is vanity.
What do people gain from all the toil
    at which they toil under the sun?
A generation goes, and a generation comes,
    but the earth remains forever.
The sun rises and the sun goes down,
    and hurries to the place where it rises.
The wind blows to the south,
    and goes around to the north;
round and round goes the wind,
    and on its circuits the wind returns.
All streams run to the sea,
    but the sea is not full;
to the place where the streams flow,
    there they continue to flow.
All things are wearisome;
    more than one can express;
the eye is not satisfied with seeing,
    or the ear filled with hearing.
What has been is what will be,
    and what has been done is what will be done;
    there is nothing new under the sun.
Is there a thing of which it is said,
    “See, this is new”?
It has already been,
    in the ages before us.
The people of long ago are not remembered,
    nor will there be any remembrance
of people yet to come
    by those who come after them.

This view is one that maintains neither progress nor regress. While there is change, the change is cyclical, and thus overall things remain the same. This is much like Aristotle’s view of the eternity of the world, although Qoheleth presumably accepts the account of Genesis 1.

Since change implies becoming better or becoming worse, and not all changes are normally undone, it is very hard in practice to maintain such a view. Thus we saw in the post linked above that Aristotle in practice believed not only in the progress of the sciences, but that they had basically reached their perfection.

As a similar example, consider this post by P. Edmund Waldstein:

In his letter to Pliny the Younger on the proper procedure in the persecution of Christians the Emperor Trajan agrees with Pliny that no note is to be taken of libelli containing anonymous denunciations, for, “Nam et pessimi exempli nec nostri saeculi est.” (“They set a bad precedent and are not in the spirit of our age.”) Not of our age! How disappointing that a Roman emperor would sink to the level of that puppet of the contemporary self-congratulatory liberal establishment, the Prime Minister of Canada, who famously justified his cabinet selection with the moronic pseudo-reason “because it’s 2015.” I had thought that this species of idiocy only came into being after Vico, but apparently I was wrong.

If “because it’s 2015” is a “moronic pseudo-reason,” the reason for this would be that time is an accidental feature: 2015 is just one year in history, just like the year 1015, and the year 3015. This suggests a view like that of Qoheleth: times are all alike, not ordered according to better and worse. But like Aristotle, P. Edmund betrays the fact that he does not really accept such a view: “I had thought that this species of idiocy only came into being after Vico, but apparently I was wrong.” If times are all alike, all species of idiocy should exist at all times. The instinct to assume that this is not the case results from the implicit belief that things do indeed change, and indeed become better and worse: it is just that P. Edmund implicitly believes that they become worse, not better, and in this case his implicit belief was not borne out by experience.

Qoheleth in fact knows that many people assume that things are becoming worse, and he rejects this view, precisely because of his position that things are circular.  Thus he says,

Do not say, “Why were the former days better than these?”
    For it is not from wisdom that you ask this.

It is not from wisdom to ask this, because the former days were just like these ones. There is nothing new under the sun.

But if this question is not according to wisdom, then just as St. Paul says, “I have been a fool! You forced me to it,” so the present discussion forces us to ask in what way former days were better than these, and why, and in what way worse, and why.