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.

Hard Problem of Consciousness

We have touched on this in various places, and in particular in this discussion of zombies, but we are now in a position to give a more precise answer.

Bill Vallicella has a discussion of Thomas Nagel on this issue:

Nagel replies in the pages of NYRB (8 June 2017; HT: Dave Lull) to one Roy Black, a professor of bioengineering:

The mind-body problem that exercises both Daniel Dennett and me is a problem about what experience is, not how it is caused. The difficulty is that conscious experience has an essentially subjective character—what it is like for its subject, from the inside—that purely physical processes do not share. Physical concepts describe the world as it is in itself, and not for any conscious subject. That includes dark energy, the strong force, and the development of an organism from the egg, to cite Black’s examples. But if subjective experience is not an illusion, the real world includes more than can be described in this way.

I agree with Black that “we need to determine what ‘thing,’ what activity of neurons beyond activating other neurons, was amplified to the point that consciousness arose.” But I believe this will require that we attribute to neurons, and perhaps to still more basic physical things and processes, some properties that in the right combination are capable of constituting subjects of experience like ourselves, to whom sunsets and chocolate and violins look and taste and sound as they do. These, if they are ever discovered, will not be physical properties, because physical properties, however sophisticated and complex, characterize only the order of the world extended in space and time, not how things appear from any particular point of view.

The problem might be condensed into an aporetic triad:

1) Conscious experience is not an illusion.

2) Conscious experience has an essentially subjective character that purely physical processes do not share.

3) The only acceptable explanation of conscious experience is in terms of physical properties alone.

Take a little time to savor this problem. Note first that the three propositions are collectively inconsistent: they cannot all be true.  Any two limbs entail the negation of the remaining one. Note second that each limb exerts a strong pull on our acceptance.  But we cannot accept them all because they are logically incompatible.

Which proposition should we reject? Dennett, I take it, would reject (1). But that’s a lunatic solution as Professor Black seems to appreciate, though he puts the point more politely. When I call Dennett a sophist, as I have on several occasions, I am not abusing him; I am underscoring what is obvious, namely, that the smell of cooked onions, for example, is a genuine datum of experience, and that such phenomenological data trump scientistic theories.

Sophistry aside, we either reject (2) or we reject (3).  Nagel and I accept (1) and (2) and reject (3). Black, and others of the scientistic stripe, accept (1) and (3) and reject (2).

In order to see the answer to this, we can construct a Parmenidean parallel to Vallicella’s aporetic triad:

1) Distinction is not an illusion.

2) Being has an essentially objective character of actually being that distinction does not share (considering that distinction consists in the fact of not being something.)

3) The only acceptable explanation of distinction is in terms of being alone (since there is nothing but being to explain things with.)

Parmenides rejects (1) here. What approach would Vallicella take? If he wishes to take a similarly analogous approach, he should accept (1) and (2), and deny (3). And this would be a pretty commonsense approach, and perhaps the one that most people implicitly adopt if they ever think about the problem.

At the same time, it is easy to see that (3) is approximately just as obviously true as (1); and it is for this reason that Parmenides sees rejecting (1) and accepting (2) and (3) as reasonable.

The correct answer, of course, is that the three are not inconsistent despite appearances. In fact, we have effectively answered this in recent posts. Distinction is not an illusion, but a way that we understand things, as such. And being a way of understanding, it is not (as such) a way of being mistaken, and thus it is not an illusion, and thus the first point is correct. Again, being a way of understanding, it is not a way of being as such, and thus the second point is correct. And yet distinction can be explained by being, since there is something (namely relationship) which explains why it is reasonable to think in terms of distinctions.

Vallicella’s triad mentions “purely physical processes” and “physical properties,” but the idea of “physical” here is a distraction, and is not really relevant to the problem. Consider the following from another post by Vallicella:

If I understand Galen Strawson’s view, it is the first.  Conscious experience is fully real but wholly material in nature despite the fact that on current physics we cannot account for its reality: we cannot understand how it is possible for qualia and thoughts to be wholly material.   Here is a characteristic passage from Strawson:

Serious materialists have to be outright realists about the experiential. So they are obliged to hold that experiential phenomena just are physical phenomena, although current physics cannot account for them.  As an acting materialist, I accept this, and assume that experiential phenomena are “based in” or “realized in” the brain (to stick to the human case).  But this assumption does not solve any problems for materialists.  Instead it obliges them to admit ignorance of the nature of the physical, to admit that they don’t have a fully adequate idea of what the physical is, and hence of what the brain is.  (“The Experiential and the Non-Experiential” in Warner and Szubka, p. 77)

Strawson and I agree on two important points.  One is that what he calls experiential phenomena are as real as anything and cannot be eliminated or reduced to anything non-experiential. Dennett denied! The other is that there is no accounting for experiential items in terms of current physics.

I disagree on whether his mysterian solution is a genuine solution to the problem. What he is saying is that, given the obvious reality of conscious states, and given the truth of naturalism, experiential phenomena must be material in nature, and that this is so whether or not we are able to understand how it could be so.  At present we cannot understand how it could be so. It is at present a mystery. But the mystery will dissipate when we have a better understanding of matter.

This strikes me as bluster.

An experiential item such as a twinge of pain or a rush of elation is essentially subjective; it is something whose appearing just is its reality.  For qualia, esse = percipi.  If I am told that someday items like this will be exhaustively understood from a third-person point of view as objects of physics, I have no idea what this means.  The notion strikes me as absurd.  We are being told in effect that what is essentially subjective will one day be exhaustively understood as both essentially subjective and wholly objective.  And that makes no sense. If you tell me that understanding in physics need not be objectifying understanding, I don’t know what that means either.

Here Vallicella uses the word “material,” which is presumably equivalent to “physical” in the above discussion. But it is easy to see here that being material is not the problem: being objective is the problem. Material things are objective, and Vallicella sees an irreducible opposition between being objective and being subjective. In a similar way, we can reformulate Vallicella’s original triad so that it does not refer to being physical:

1) Conscious experience is not an illusion.

2) Conscious experience has an essentially subjective character that purely objective processes do not share.

3) The only acceptable explanation of conscious experience is in terms of objective properties alone.

It is easy to see that this formulation is the real source of the problem. And while Vallicella would probably deny (3) even in this formulation, it is easy to see why people would want to accept (3). “Real things are objective,” they will say. If you want to explain anything, you should explain it using real things, and therefore objective things.

The parallel with the Parmenidean problem is evident. We would want to explain distinction in terms of being, since there isn’t anything else, and yet this seems impossible, so one (e.g. Parmenides) is tempted to deny the existence of distinction. In the same way, we would want to explain subjective experience in terms of objective facts, since there isn’t anything else, and yet this seems impossible, so one (e.g. Dennett) is tempted to deny the existence of subjective experience.

Just as the problem is parallel, the correct solution will be almost entirely parallel to the solution to the problem of Parmenides.

1) Conscious experience is not an illusion. It is a way of perceiving the world, not a way of not perceiving the world, and definitely not a way of not perceiving at all.

2) Consciousness is subjective, that is, it is a way that an individual perceives the world, not a way that things are as such, and thus not an “objective fact” in the sense that “the way things are” is objective.

3) The “way things are”, namely the objective facts, are sufficient to explain why individuals perceive the world. Consider again this post, responding to a post by Robin Hanson. We could reformulate his criticism to express instead Parmenides’s criticism of common sense (changed parts in italics):

People often state things like this:

I am sure that there is not just being, because I’m aware that some things are not other things. I know that being just isn’t non-being. So even though there is being, there must be something more than that to reality. So there’s a deep mystery: what is this extra stuff, where does it arise, how does it change, and so on. We humans care about distinctions, not just being; we want to know what out there is distinct from which other things.

But consider a key question: Does this other distinction stuff interact with the parts of our world that actually exist strongly and reliably enough to usually be the actual cause of humans making statements of distinction like this?

If yes, this is a remarkably strong interaction, making it quite surprising that philosophers, possibly excepting Duns Scotus, have missed it so far. So surprising in fact as to be frankly unbelievable. If this type of interaction were remotely as simple as all the interactions we know, then it should be quite understandable with existing philosophy. Any interaction not so understandable would have be vastly more difficult to understand than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will understand such an interaction.

But if no, if this interaction isn’t strong enough to explain human claims of distinction, then we have a remarkable coincidence to explain. Somehow this extra distinction stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that distinction stuff exists isn’t causing people to claim it exists, nor vice versa. Instead humans have some sort of weird psychological quirk that causes them to make such statements, and they would make such claims even if distinction stuff didn’t exist. But if we have a good alternate explanation for why people tend to make such statements, what need do we have of the hypothesis that distinction stuff actually exists? Such a coincidence seems too remarkable to be believed.

“Distinction stuff”, of course, does not exist, and neither does “feeling stuff.” But some things are distinct from others. Saying this is a way of understanding the world, and it is a reasonable way to understand the world because things exist relative to one another. And just as one thing is distinct from another, people have experiences. Those experiences are ways of knowing the world (broadly understood.) And just as reality is sufficient to explain distinction, so reality is sufficient to explain the fact that people have experiences.

How exactly does this answer the objection about interaction? In the case of distinction, the fact that “one thing is not another” is never the direct cause of anything, not even of the fact that “someone believes that one thing is not another.” So there would seem to be a “remarkable coincidence” here, or we would have to say that since the fact seems unrelated to the opinion, there is no reason to believe people are right when they make distinctions.

The answer in the case of distinction is that one thing is related to another, and this fact is the cause of someone believing that one thing is not another. There is no coincidence, and no reason to believe that people are mistaken when they make distinctions, despite the fact that distinction as such causes nothing.

In a similar way, “a human being is what it is,” and “a human being does what it does” (taken in an objective sense), cause human beings to say and believe that they have subjective experience (taking saying and believing to refer to objective facts.) But this is precisely where the zombie question arises: they say and believe that they have subjective experience, when we interpret say and believe in the objective sense. But do they actually say and believe anything, considering saying and believing as including the subjective factor? Namely, when a non-zombie says something, it subjectively understands the meaning of what it is saying, and when it consciously believes something, it has a subjective experience of doing that, but these things would not apply to a zombie.

But notice that we can raise a similar question about zombie distinctions. When someone says and believes that one thing is not another, objective reality is similarly the cause of them making the distinction. But is the one thing actually not the other? But there is no question at all here except of whether the person’s statement is true or false. And indeed, someone can say, e.g, “The person who came yesterday is not the person who came today,” and this can sometimes be false. In a similar way, asking whether an apparent person is a zombie or not is just asking whether their claim is true or false when they say they have a subjective experience. The difference is that if the (objective) claim is false, then there is no claim at all in the subjective sense of “subjectively claiming something.” It is a contradiction to subjectively make the false claim that you are subjectively claiming something, and thus, this cannot happen.

Someone may insist: you yourself, when you subjectively claim something, cannot be mistaken for the above reason. But you have no way to know whether someone else who apparently is making that claim, is actually making the claim subjectively or not. This is the reason there is a hard problem.

How do we investigate the case of distinction? If we want to determine whether the person who came yesterday is not the person who came today, we do that by looking at reality, despite the fact that distinction as such is not a part of reality as such. If the person who came yesterday is now, today, a mile away from the person who came today, this gives us plenty of reason to say that the one person is not the other. There is nothing strange, however, in the fact that there is no infallible method to prove conclusively, once and for all, that one thing is definitely not another thing. There is not therefore some special “hard problem of distinction.” This is just a result of the fact that our knowledge in general is not infallible.

In a similar way, if we want to investigate whether something has subjective experience or not, we can do that only by looking at reality: what is this thing, and what does it do? Then suppose it makes an apparent claim that it has subjective experience. Obviously, for the above reasons, this cannot be a subjective claim but false: so the question is whether it makes a subjective claim and is right, or rather makes no subjective claim at all. How would you answer this as an external observer?

In the case of distinction, the fact that someone claims that one thing is distinct from another is caused by reality, whether the claim is true or false. So whether it is true or false depends on the way that it is caused by reality. In a similar way, the thing which apparently and objectively claims to possess subjective experience, is caused to do so by objective facts. Again, as in the case of distinction, whether it is true or false will depend on the way that it is caused to do so by objective facts.

We can give some obvious examples:

“This thing claims to possess subjective experience because it is a human being and does what humans normally do.” In this case, the objective and subjective claim is true, and is caused in the right way by objective facts.

“This thing claims to possess subjective experience because it is a very simple computer given a very simple program to output ‘I have subjective experience’ on its screen.” In this case the external claim is false, and it is caused in the wrong way by objective facts, and there is no subjective claim at all.

But how do you know for sure, someone will object. Perhaps the computer really is conscious, and perhaps the apparent human is a zombie. But we could similarly ask how we can know for sure that the person who came yesterday isn’t the same person who came today, even though they appear distant from each other, because perhaps the person is bilocating?

It would be mostly wrong to describe this situation by saying “there really is no hard problem of consciousness,” as Robin Hanson appears to do when he says, “People who think they can conceive of such zombies see a ‘hard question’ regarding which physical systems that claim to feel and otherwise act as if they feel actually do feel.” The implication seems to be that there is no hard question at all. But there is, and the fact that people engage in this discussion proves the existence of the question. Rather, we should say that the question is answerable, and that one it has been answered the remaining questions are “hard” only in the sense that it is hard to understand the world in general. The question is hard in exactly the way the question of Parmenides is hard: “How is it possible for one thing not to be another, when there is only being?” The question of consciousness is similar: “How is it possible for something to have subjective experience, when there are only objective things?” And the question can and should be answered in a similar fashion.

It would be virtually impossible to address every related issue in a simple blog post of this form, so I will simply mention some things that I have mainly set aside here:

1) The issue of formal causes, discussed more in my earlier treatment of this issue. This is relevant because “is this a zombie?” is in effect equivalent to asking whether the thing lacks a formal cause. This is worthy of a great deal of consideration and would go far beyond either this post or the earlier one.

2) The issue of “physical” and “material.” As I stated in this post, this is mainly a distraction. Most of the time, the real question is how the subjective is possible given that we believe that the world is objective. The only relevance of “matter” here is that it is obvious that a material thing is an objective thing. But of course, an immaterial thing would also have to be objective in order to be a thing at all. Aristotle and many philosophers of his school make the specific argument that the human mind does not have an organ, but such arguments are highly questionable, and in my view fundamentally flawed. My earlier posts suffice to call such a conclusion into question, but do not attempt to disprove it, and the the topic would be worthy of additional consideration.

3) Specific questions about “what, exactly, would actually be conscious?” Now neglecting such questions might seem to be a cop-out, since isn’t this what the whole problem was supposed to be in the first place? But in a sense we did answer it. Take an apparent claim of something to be conscious. The question would be this: “Given how it was caused by objective facts to make that claim, would it be a reasonable claim for a subjective claimer to make?” In other words, we cannot assume in advance that it is subjectively making a claim, but if it would be a reasonable claim, it will (in general) be a true one, and therefore also a subjective one, for the same reason that we (in general) make true claims when we reasonably claim that one thing is not another. We have not answered this question only in the same sense that we have not exhaustively explained which things are distinct from which other things, and how one would know. But the question, e.g., “when if ever would you consider an artificial intelligence to be conscious?” is in itself also worthy of direct discussion.

4) The issue of vagueness. This issue in particular will cause some people to object to my answer here. Thus Alexander Pruss brings this up in a discussion of whether a computer could be conscious:

Now, intelligence could plausibly be a vague property. But it is not plausible that consciousness is a vague property. So, there must be some precise transition point in reliability needed for computation to yield consciousness, so that a slight decrease in reliability—even when the actual functioning is unchanged (remember that the Ci are all functioning in the same way)—will remove consciousness.

I responded in the comments there:

The transition between being conscious and not being conscious that happens when you fall asleep seems pretty vague. I don’t see why you find it implausible that “being conscious” could be vague in much the same way “being red” or “being intelligent” might be vague. In fact the evidence from experience (falling asleep etc) seems to directly suggest that it is vague.

Pruss responds:

When I fall asleep, I may become conscious of less and less. But I can’t get myself to deny that either it is definitely true at any given time that I am at least a little conscious or it is definitely true that I am not at all conscious.

But we cannot trust Pruss’s intuitions about what can be vague or otherwise. Pruss claims in an earlier post that there is necessarily a sharp transition between someone’s not being old and someone’s being old. I discussed that post here. This is so obviously false that it gives us a reason in general not to trust Alexander Pruss on the issue of sharp transitions and vagueness. The source of this particular intuition may be the fact that you cannot subjectively make a claim, even vaguely, without some subjective experience, as well as his general impression that vagueness violates the principles of excluded middle and non-contradiction. But in a similar way, you cannot be vaguely old without being somewhat old. This does not mean that there is a sharp transition from not being old to being old, and likewise it does not necessarily mean that there is a sharp transition from not having subjective experience to having it.

While I have discussed the issue of vagueness elsewhere on this blog, this will probably continue to be a reoccurring feature, if only because of those who cannot accept this feature of reality and insist, in effect, on “this or nothing.”