Form and Reality

In a very interesting post Alexander Pruss discusses realism and skeptical scenarios:

The ordinary sentence “There are four chairs in my office” is true (in its ordinary context). Furthermore, its being true tells us very little about fundamental ontology. Fundamental physical reality could be made out of a single field, a handful of fields, particles in three-dimensional space, particles in ten-dimensional space, a single vector in a Hilbert space, etc., and yet the sentence could be true.

An interesting consequence: Even if in fact physical reality is made out of particles in three-dimensional space, we should not analyze the sentence to mean that there are four disjoint pluralities of particles each arranged chairwise in my office. For if that were what the sentence meant, it would tell us about which of the fundamental physical ontologies is correct. Rather, the sentence is true because of a certain arrangement of particles (or fields or whatever).

If there is such a broad range of fundamental ontologies that “There are four chairs in my office” is compatible with, it seems that the sentence should also be compatible with various sceptical scenarios, such as that I am a brain in a vat being fed data from a computer simulation. In that case, the chair sentence would be true due to facts about the computer simulation, in much the way that “There are four chairs in this Minecraft house” is true. It would be very difficult to be open to a wide variety of fundamental physics stories about the chair sentence without being open to the sentence being true in virtue of facts about a computer simulation.

But now suppose that the same kind of thing is true for other sentences about physical things like tables, dogs, trees, human bodies, etc.: each of these sentences can be made true by a wide array of physical ontologies. Then it seems that nothing we say about physical things rules out sceptical scenarios: yes, I know I have two hands, but my having two hands could be grounded by facts about a computer simulation. At this point the meaningfulness of the sceptical question whether I know I am not a brain in a vat is breaking down. And with it, realism is breaking down.

I am not completely sure what Pruss means by “realism is breaking down,” but he is looking at something important here. One question that needs to be addressed, however, is what counts as a skeptical scenario in the first place. In the rest of the post, Pruss makes an interesting suggestion about this:

In order for the sceptical question to make sense, we need the possibility of saying things that cannot simply be made true by a very wide variety of physical theories, since such things will also be made true by computer simulations. This gives us an interesting anti-reductionist argument. If the statement “I have two hands” is to be understood reductively (and I include non-Aristotelian functionalist views as reductive), then it could still be literally true in the brain-in-a-vat scenario. But if anti-reductionism about hands is true, then the statement wouldn’t be true in the brain-in-a-vat scenario. And so I can deny that I am in that scenario simply by saying “I have two hands.”

But maybe I am moving too fast here. Maybe “I have two hands” could be literally true in a brain-in-a-vat scenario. Suppose that the anti-reductionism consists of there being Aristotelian forms of hands (presumably accidental forms). But if, for all we know, the form of a hand can inform a bunch of particles, a fact about a vector or the region of a field, then the form of a hand can also inform an aspect of a computer simulation. And so, for all we know, I can literally and non-reductively have hands even if I am a brain in a vat. I am not sure, however, that I need to worry about this. What is important is form, not the precise material substrate. If physical reality is the memory of a giant computer but it isn’t a mere simulation but is in fact informed by a multiplicity of substantial and accidental forms corresponding to people, trees, hands, hearts, etc., and these forms are real entities, then the scenario does not seem to me to be a sceptical scenario.

A skeptical scenario, according to Pruss, is a situation where the things we normally talk about do not have forms. If they do have forms, we are not in a skeptical scenario at all, even if in some sense we are in a computer simulation or even if someone is a brain in a vat. On the face of it this seems a very odd claim: “form” seems to be a technical philosophical explanation, while asking if we are in a skeptical scenario seems to be asking if our everyday common sense understanding of things is mistaken.

Nonetheless, there is a lot of truth in his explanation. First let us consider what is meant by a skeptical scenario in the first place. In terms of his example, it is supposed to go something like this: “Is it possible that you are a brain in a vat without realizing it? If so, then almost everything you believe is false, since you do not have hands, the people you speak to are not real, and so on.”

In the post Pruss is pointing out a problem with the skeptical question. The skeptical question is like a skeptic in the remote past asking, “Is it possible that the earth is spinning without us realizing it? If so, then our everyday opinion that the sun rises every morning is false, since the sun does not move.”

The response to the second skeptic is evident: our everyday opinion that the sun rises every morning is not false, not even if the earth turns out to be spinning, because “the sun rises every morning,” is to be understood in whatever way is needed in order for it to be true. It refers to what happens every morning, whatever that actually happens to be.

Pruss is pointing out that we can answer the first question in the same way: our everyday opinion that we have hands is not false, not even if we are in a computer simulation or in a vat, because “I have two hands” is to be understood in whatever way is needed in order for it to be true. It refers to these two things in front of me right now, whatever they actually are.

Let’s suppose the skeptic tries to come up with a response. He might say, “Look, computer programs do not have hands, and brains do not have hands. So if you are a computer program or a brain in a vat, then you just do not have hands, period. So those scenarios do indeed mean that your common understanding would be false.”

It is certainly true that according to our common understanding, brains in vats do not have hands. So there is a tension here: the argument that it would be true to say we have hands even in that situation seems like a good argument, but so does the argument that it would be false that we have hands.

The answer to the difficulty is that we need to consider the meaning of “I am a brain in a vat.” Just as the word “hands” should refer to these two things in front of me, whatever they are, so the word “brain” refers to things inside of people’s heads, whatever they are, and the word “vat” refers to other things we sometimes experience in real life, at occasionally, or something very like them. But this means that just as “I have two hands” is to be understood in whatever way is needed to make it true, so also “I am not a brain in a vat,” is understood in whatever way is needed to make it true.

This means that correct answer to the original question was simply, “No, it isn’t possible that I will turn out to be a brain in a vat, regardless of any later discoveries, and it isn’t possible that the sun will turn out not to rise, regardless of discoveries about the motion of the sun and of the earth.”

The skeptic will want to insist. Surely events like those of The Matrix are at least conceivable. And if some such situation turned out to be true, then wasn’t it true that you were in a skeptical scenario and that your beliefs about hands and brains and vats were all false, and especially would it not be the case that your belief that you weren’t in a situation like that was false?

The correct answer, again, is that your original beliefs were not false. But in view of your new knowledge of the world, you might well want to adopt a new mode of speaking, and say things that would sound opposed to your original beliefs. They would not be opposed, however, but would simply be speaking about things you did not originally speak about.

Note however that “your belief that you weren’t in a situation like that” could now be taken in two ways. It could mean my belief that I am not a brain in a vat, and this belief will never turn out to have been false. Or it could mean a belief that there is not some larger view of reality where “he was a brain in a vat” would be a reasonable description, in the way that someone coming out of the Matrix would acquire a larger view. In reality I have the latter belief as well, as I consider it improbable that any intelligent beings would behave in such a way as to make that scenario probable. But I don’t think it is impossible for this belief to be falsified; and if it were, I would not say that my previous common sense beliefs had been false. This corresponds to what Pruss says at the end of his post, where he says that as long as things have forms, it is not really a skeptical scenario, even if in some sense he is in a computer simulation or whatever.

Why the insistence on form? This is related to what we called the Semi-Parmenidean Heresy. There we discussed Sean Carroll’s view, and noted that his position in essence is this: Metaphysically, the eliminativists are right. But it is useful to talk as though they are wrong, so we’re going to talk as though they are wrong, and even say they are wrong, by saying that common sense things are real.

This is ultimately incoherent: if the eliminativists are mistaken, they are mistaken in their metaphysics, since the position is just a certain metaphysical position.

It is not difficult to see the connection. According to a strict eliminativist, it would be literally true that we do not have hands, because there is no such thing as “we” or as “hands” in the first place. There are just fundamental particles. In other words, eliminativism would be even more of a skeptical scenario than the Matrix; the Matrix would not imply that your common sense beliefs are false, while eliminativism simply says that all of your beliefs are false, including your belief that you have beliefs.

And on the other hand, no scenario will be truly skeptical, even one like the Matrix, if it admits that our common sense beliefs are true. And as I said at the end of the post on Carroll’s view, this requires a metaphysics that allows those beliefs to be true, and this requires formal causes.

Alexander Pruss, however, seems to me to interpret this in a rather narrow way in his concluding remark:

If physical reality is the memory of a giant computer but it isn’t a mere simulation but is in fact informed by a multiplicity of substantial and accidental forms corresponding to people, trees, hands, hearts, etc., and these forms are real entities, then the scenario does not seem to me to be a sceptical scenario.

It is not clear what it means to be “real entities” rather than being unreal, given that you acknowledge them in the first place, and it isn’t clear to me what he means by a “mere simulation.” But this sounds a lot to me like, “If the world isn’t Aristotelian, understood in a very narrow way, then that would be a skeptical scenario.” This seems to me a kind of stubbornness much like that of James Larson. Disagreeing with you is not a war against being, and believing that your account of form and matter didn’t get every detail right, is not saying that our common sense beliefs are not true.

As an illustration of the narrowness in question, consider Pruss’s position on artifacts:

Suppose I am a plumber, and I take a section of pipe, insert a blowgun dart, and blow.  I just shot a dart out of a blowgun.  When did the pipe turn into a blowgun, though?

Did it happen when I formed the intention to use the pipe as a blowgun?  No: I do not have the power to make new material objects come into existence just by thinking about it.

When I picked up the pipe?  There are at least there is contact.  But surely it’s not the right kind of contact.  It would be magic if I could make a new material object come into existence by just picking up a material object with a certain thought in mind.

When I inserted the dart?  Presumably, not any insertion will do, but one with a plan to blow.  For I could just be doing plumbing, using the outer diameter of the dart to measure the inner diameter of the pipe, and that shouldn’t turn the pipe into a dart.  Again, we have some magic here–thinking about the pipe in one way while inserting the dart creates a blowgun while thinking about it another way leaves it a boring pipe.  Moreover, putting the dart into the pipe seems to be an instance of loading a blowgun rather than making a blowgun.

The solution to all this is to deny that there are pipes and blowguns.  There is just matter (or fields) arranged pipewise and blowgunwise.  And for convenience we adopt ways of speaking that make it sound like such objects are among the furniture of the universe.

Pruss is not simply putting out a position for discussion; this is what he believes to be true, as is easily confirmed elsewhere on his blog. Note that he is falling into the Semi-Parmenidean heresy here, except that he is even going farther than Carroll, and suggesting that “there are no pipes and blowguns” is a true statement, which Carroll would rightly deny. In this way Pruss is almost a pure eliminativist about artifacts. (He does also speak elsewhere more in the manner of Sean Carroll about them.)

To the degree that he is eliminativist about artifacts, he contradicts common sense in the same kind of way that someone contradicts common sense who says, “You do not have hands.” He just contradicts it about different things. And why about these things, and not others? I suggest that it is because under the ordinary Aristotelian account, it is likely that a man or a horse has a substantial form, but unlikely that a pipe has one. And although a pipe would have various accidental forms, the idea of a unified form of “pipeness” seems pretty unlikely. If this is actually his reason or part of it, then he is identifying skepticism with disagreeing with his philosophical opinions, even though his own opinions actually contain the skepticism: namely, disagreement with common sense.

My own response to this question would be different: being is said in many ways, and consequently also form and unity. And I reject any disagreement with common sense: men and horses are real, but so also are pipes. If I am not mistaken, all of these will have being and form in the way that is appropriate to them.

Semi-Parmenidean Heresy

In his book The Big Picture, Sean Carroll describes the view which he calls “poetic naturalism”:

As knowledge generally, and science in particular, have progressed over the centuries, our corresponding ontologies have evolved from quite rich to relatively sparse. To the ancients, it was reasonable to believe that there were all kinds of fundamentally different things in the world; in modern thought, we try to do more with less.

We would now say that Theseus’s ship is made of atoms, all of which are made of protons, neutrons, and electrons-exactly the same kinds of particles that make up every other ship, or for that matter make up you and me. There isn’t some primordial “shipness” of which Theseus’s is one particular example; there are simply arrangements of atoms, gradually changing over time.

That doesn’t mean we can’t talk about ships just because we understand that they are collections of atoms. It would be horrendously inconvenient if, anytime someone asked us a question about something happening in the world, we limited our allowable responses to a listing of a huge set of atoms and how they were arranged. If you listed about one atom per second, it would take more than a trillion times the current age of the universe to describe a ship like Theseus’s. Not really practical.

It just means that the notion of a ship is a derived category in our ontology, not a fundamental one. It is a useful way of talking about certain subsets of the basic stuff of the universe. We invent the concept of a ship because it is useful to us, not because it’s already there at the deepest level of reality. Is it the same ship after we’ve gradually replaced every plank? I don’t know. It’s up to us to decide. The very notion of “ship” is something we created for our own convenience.

That’s okay. The deepest level of reality is very important; but all the different ways we have of talking about that level are important too.

There is something essentially pre-Socratic about this thinking. When Carroll talks about “fundamentally different things,” he means things that differ according to their basic elements. But at the same kind the implication is that only things that differ in this way are “fundamentally” different in the sense of being truly or really different. But this is a quite different sense of “fundamental.”

I suggested in the linked post that even Thales might not really have believed that material causes alone sufficiently explained reality. Nonetheless, there was a focus on the material cause as being the truest explanation. We see the same focus here in Sean Carroll. When he says, “There isn’t some primordial shipness,” he is thinking of shipness as something that would have to be a material cause, if it existed.

Carroll proceeds to contrast his position with eliminativism:

One benefit of a rich ontology is that it’s easy to say what is “real”- every category describes something real. In a sparse ontology, that’s not so clear. Should we count only the underlying stuff of the world as real, and all the different ways we have of dividing it up and talking about it as merely illusions? That’s the most hard-core attitude we could take to reality, sometimes called eliminativism, since its adherents like nothing better than to go around eliminating this or that concept from our list of what is real. For an eliminativist, the question “Which Captian Kirk is the real one?” gets answered by, “Who cares? People are illusions. They’re just fictitious stories we tell about the one true world.”

I’m going to argue for a different view: our fundamental ontology, the best way we have of talking about the world at the deepest level, is extremely sparse. But many concepts that are part of non-fundamental ways we have of talking about the world- useful ideas describing higher-level, macroscopic reality- deserve to be called “real.”

The key word there is “useful.” There are certainly non-useful ways of talking about the world. In scientific contexts, we refer to such non-useful ways as “wrong” or “false.” A way of talking isn’t just a list of concepts; it will generally include a set of rules for using them, and relationships among them. Every scientific theory is a way of talking about the world, according to which we can say things like “There are things called planets, and something called the sun, all of which move through something called space, and planets do something called orbiting the sun, and those orbits describe a particular shape in space called an ellipse.” That’s basically Johannes Kepler’s theory of planetary motion, developed after Copernicus argued for the sun being at the center of the solar system but before Isaac Newton explained it all in terms of the force of gravity. Today, we would say that Kepler’s theory is fairly useful in certain circumstances, but it’s not as useful as Newton’s, which in turn isn’t as broadly useful as Einstein’s general theory of relativity.

A poetic naturalist will agree that both Captain Kirk and the Ship of Theseus are simply ways of talking about certain collections of atoms stretching through space and time. The difference is that an eliminativist will say “and therefore they are just illusions,” while the poetic naturalist says “but they are no less real for all of that.”

There are some good things about what Carroll is doing here. He is right of course to insist that the things of common experience are “real.” He is also right to see some relationship between saying that something is real and saying that talking about it is useful, but this is certainly worth additional consideration, and he does not really do it justice.

The problematic part is that, on account of his pre-Socratic tendencies, he is falling somewhat into the error of Parmenides. The error of Parmenides was to suppose that being can be, and can be thought and said, in only one way. Carroll, on account of confusing the various meanings of “fundamental,” supposes that being can be in only one way, namely as something elemental, but that it can be thought and said in many ways.

The problem with this, apart from the falsity of asserting that being can be in only one way, is that no metaphysical account is given whereby it would be reasonable to say that being can be thought and said in many ways, given that it can be in only one way. Carroll is trying to point in that direction by saying that our common speech is useful, so it must be about real things; but the eliminativist would respond, “Useful to whom? The things that you are saying this is useful for are illusions and do not exist. So even your supposed usefulness does not exist.” And Carroll will have no valid response, because he has already admitted to agreeing with the eliminativist on a metaphysical level.

The correct answer to this is the one given by Aristotle. Material causes do not sufficiently explain reality, but other causes are necessary as well. But this means that the eliminativist is mistaken on a metaphysical level, not merely in his way of speaking.

Knowing Knowing is Secondary

It would be a mistake in general to suppose that one could derive all important truths from a few first principles, but one particular way to fall into this error would be to think that one can or should derive metaphysics or other branches of scientific or philosophical knowledge from epistemology. One reason for this is implied by the previous post: insofar as we come to know knowledge from a knowledge of the known or knowable, it is never possible to begin by thinking about knowledge, but one must begin by thinking about things.

Descartes’s discussion of the scenario of the evil demon appears to be an example of this error, insofar as he seems to suggest that his first knowledge is of the fact that he is thinking something. In fact, it is quite evident that one must know oneself in order to have the thought, “I am thinking,” and that one would never think about thinking without first thinking about something else.

Still, Descartes’s adoption of this error is only partial. He does realize that this is not the natural order of coming to know. Thus in the Synopsis of his Meditations he says:

Finally in the Sixth I distinguish the action of the understanding from that of the imagination; the marks by which this distinction is made are described. I here show that the mind of man is really distinct from the body, and at the same time that the two are so closely joined together that they form, so to speak, a single thing. All the errors which proceed from the senses are then surveyed, while the means of avoiding them are demonstrated, and finally all the reasons from which we may deduce the existence of material things are set forth. Not that I judge them to be very useful in establishing that which they prove, to wit, that there is in truth a world, that men possess bodies, and other such things which never have been doubted by anyone of sense; but because in considering these closely we come to see that they are neither so strong nor so evident as those arguments which lead us to the knowledge of our mind and of God; so that these last must be the most certain and most evident facts which can fall within the cognizance of the human mind. And this is the whole matter that I have tried to prove in these Meditations, for which reason I here omit to speak of many other questions which I dealt incidentally in this discussion.
Descartes cannot be excused from error here insofar as he asserts that “the knowledge of our mind and of God” are “the most certain and most evident facts” that we can know, but he does realize that people do not actually deduce the existence of an external world from the fact that they think. This is why he admits that such things “never have been doubted by anyone of sense.”

Evil Demon

Descartes begins his Meditations on First Philosophy:

It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis; and from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences.

In order to do this, he says, it is necessary to doubt all of his former opinions. So he invents a hypothesis to render them doubtful:

I shall then suppose, not that God who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me; I shall consider that the heavens, the earth, colours, figures, sound, and all other external things are nought but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity; I shall consider myself as having no hands, no eyes, no flesh, no blood, nor any senses, yet falsely believing myself to possess all these things; I shall remain obstinately attached to this idea, and if by this means it is not in my power to arrive at the knowledge of any truth, I may at least do what is in my power [i.e. suspend my judgment], and with firm purpose avoid giving credence to any false thing, or being imposed upon by this arch deceiver, however powerful and deceptive he may be. But this task is a laborious one, and insensibly a certain lassitude leads me into the course of my ordinary life. And just as a captive who in sleep enjoys an imaginary liberty, when he begins to suspect that his liberty is but a dream, fears to awaken, and conspires with these agreeable illusions that the deception may be prolonged, so insensibly of my own accord I fall back into my former opinions, and I dread awakening from this slumber, lest the laborious wakefulness which would follow the tranquility of this repose should have to be spent not in daylight, but in the excessive darkness of the difficulties which have just been discussed.

He continues with his second meditation:

The Meditation of yesterday filled my mind with so many doubts that it is no longer in my power to forget them. And yet I do not see in what manner I can resolve them; and, just as if I had all of a sudden fallen into very deep water, I am so disconcerted that I can neither make certain of setting my feet on the bottom, nor can I swim and so support myself on the surface. I shall nevertheless make an effort and follow anew the same path as that on which I yesterday entered, i.e. I shall proceed by setting aside all that in which the least doubt could be supposed to exist, just as if I had discovered that it was absolutely false; and I shall ever follow in this road until I have met with something which is certain, or at least, if I can do nothing else, until I have learned for certain that there is nothing in the world that is certain. Archimedes, in order that he might draw the terrestrial globe out of its place, and transport it elsewhere, demanded only that one point should be fixed and immoveable; in the same way I shall have the right to conceive high hopes if I am happy enough to discover one thing only which is certain and indubitable. I suppose, then, that all the things that I see are false; I persuade myself that nothing has ever existed of all that my fallacious memory represents to me. I consider that I possess no senses; I imagine that body, figure, extension, movement and place are but the fictions of my mind. What, then, can be esteemed as true? Perhaps nothing at all, unless that there is nothing in the world that is certain. But how can I know there is not something different from those things that I have just considered, of which one cannot have the slightest doubt? Is there not some God, or some other being by whatever name we call it, who puts these reflections into my mind? That is not necessary, for is it not possible that I am capable of producing them myself? I myself, am I not at least something? But I have already denied that I had senses and body. Yet I hesitate, for what follows from that? Am I so dependent on body and senses that I cannot exist without these? But I was persuaded that there was nothing in all the world, that there was no heaven, no earth, that there were no minds, nor any bodies: was I not then likewise persuaded that I did not exist? Not at all; of a surety I myself did exist since I persuaded myself of something [or merely because I thought of something]. But there is some deceiver or other, very powerful and very cunning, who ever employs his ingenuity in deceiving me. Then without doubt I exist also if he deceives me, and let him deceive me as much as he will, he can never cause me to be nothing so long as I think that I am something. So that after having reflected well and carefully examined all things, we must come to the definite conclusion that this proposition: I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive it.

Descartes’s demon is not very powerful. Otherwise, why should it not deceive him into believing that it is necessarily true that he must exist in order to think that he exists, even if this is false? In other words, it may be that Descartes can think that he exists even without existing, but the evil demon can deceive him into believing that it is perfectly obvious that this is impossible.

The situation is of course incoherent. But it would also be incoherent for two and two not to make four, and presumably Descartes meant to call this into question as well, or his existence would no longer have the special place of primacy that he is giving it here.

We noted earlier that in order to have a good conversation, we need to concede something to our conversational partner. We can take to this to its ultimate limit by noting that we cannot hold a conversation at all with someone who will not respond except in order to say, “no, that’s wrong.” Suggesting that an evil demon hypothesis (or some equivalent) is true about someone is in effect replying to everything he says in this way. Likewise, suggesting that such a hypothesis might be true about someone, in the sense that there is a substantial doubt about the hypothesis, is in effect responding to everything with, “you might be wrong anyway,” which will be no more effective in producing a conversation.