Structure of Explanation

When we explain a thing, we give a cause; we assign the thing an origin that explains it.

We can go into a little more detail here. When we ask “why” something is the case, there is always an implication of possible alternatives. At the very least, the question implies, “Why is this the case rather than not being the case?” Thus “being the case” and “not being the case” are two possible alternatives.

The alternatives can be seen as possibilities in the sense explained in an earlier post. There may or may not be any actual matter involved, but again, the idea is that reality (or more specifically some part of reality) seems like something that would be open to being formed in one way or another, and we are asking why it is formed in one particular way rather than the other way. “Why is it raining?” In principle, the sky is open to being clear, or being filled with clouds and a thunderstorm, and to many other possibilities.

A successful explanation will be a complete explanation when it says “once you take the origin into account, the apparent alternatives were only apparent, and not really possible.” It will be a partial explanation when it says, “once you take the origin into account, the other alternatives were less sensible (i.e. made less sense as possibilities) than the actual thing.”

Let’s consider some examples in the form of “why” questions and answers.

Q1. Why do rocks fall? (e.g. instead of the alternatives of hovering in the air, going upwards, or anything else.)

A1. Gravity pulls things downwards, and rocks are heavier than air.

The answer gives an efficient cause, and once this cause is taken into account, it can be seen that hovering in the air or going upwards were not possibilities relative to that cause.

Obviously there is not meant to be a deep explanation here; the point here is to discuss the structure of explanation. The given answer is in fact basically Newton’s answer (although he provided more mathematical detail), while with general relativity Einstein provided a better explanation.

The explanation is incomplete in several ways. It is not a first cause; someone can now ask, “Why does gravity pull things downwards, instead of upwards or to the side?” Similarly, while it is in fact the cause of falling rocks, someone can still ask, “Why didn’t anything else prevent gravity from making the rocks fall?” This is a different question, and would require a different answer, but it seems to reopen the possibility of the rocks hovering or moving upwards, from a more general point of view. David Hume was in part appealing to the possibility of such additional questions when he said that we can see no necessary connection between cause and effect.

Q2. Why is 7 prime? (i.e. instead of the alternative of not being prime.)

A2. 7/2 = 3.5, so 7 is not divisible by 2. 7/3 = 2.333…, so 7 is not divisible by 3. In a similar way, it is not divisible by 4, 5, or 6. Thus in general it is not divisible by any number except 1 and itself, which is what it means to be prime.

If we assumed that the questioner did not know what being prime means, we could have given a purely formal response simply by noting that it is not divisible by numbers between 1 and itself, and explaining that this is what it is to be prime. As it is, the response gives a sufficient material disposition. Relative to this explanation, “not being prime,” was never a real possibility for 7 in the first place. The explanation is complete in that it completely excludes the apparent alternative.

Q3. Why did Peter go to the store? (e.g. instead of going to the park or the museum, or instead of staying home.)

A3. He went to the store in order to buy groceries.

The answer gives a final cause. In view of this cause the alternatives were merely apparent. Going to the park or the museum, or even staying home, were not possible since there were no groceries there.

As in the case of the rock, the explanation is partial in several ways. Someone can still ask, “Why did he want groceries?” And again someone can ask why he didn’t go to some other store, or why something didn’t hinder him, and so on. Such questions seem to reopen various possibilities, and thus the explanation is not an ultimately complete one.

Suppose, however, that someone brings up the possibility that instead of going to the store, he could have gone to his neighbor and offered money for groceries in his neighbor’s refrigerator. This possibility is not excluded simply by the purpose of buying groceries. Nonetheless, the possibility seems less sensible than getting them from the store, for multiple reasons. Again, the implication is that our explanation is only partial: it does not completely exclude alternatives, but it makes them less sensible.

Let’s consider a weirder question: Why is there something rather than nothing?

Now the alternatives are explicit, namely there being something, and there being nothing.

It can be seen that in one sense, as I said in the linked post, the question cannot have an answer, since there cannot be a cause or origin for “there is something” which would itself not be something. Nonetheless, if we consider the idea of possible alternatives, it is possible to see that the question does not need an answer; one of the alternatives was only an apparent alternative all along.

In other words, the sky can be open to being clear or cloudy. But there cannot be something which is open both to “there is something” and “there is nothing”, since any possibility of that kind would be “something which is open…”, which would already be something rather than nothing. The “nothing” alternative was merely apparent. Nothing was ever open to there being nothing.

Let’s consider another weird question. Suppose we throw a ball, and in the middle of the path we ask, Why is the ball in the middle of the path instead of at the end of the path?

We could respond in terms of a sufficient material disposition: it is in the middle of the path because you are asking your question at the middle, instead of waiting until the end.

Suppose the questioner responds: Look, I asked my question at the middle of the path. But that was just chance. I could have asked at any moment, including at the end. So I want to know why it was in the middle without considering when I am asking the question.

If we look at the question in this way, it can be seen in one way that no cause or origin can be given. Asked in this way, being at the end cannot be excluded, since they could have asked their question at the end. But like the question about something rather than nothing, the question does not need an answer. In this case, this is not because the alternatives were merely apparent in the sense that one was possible and the other not. But they were merely apparent in the sense that they were not alternatives. The ball goes both goes through the middle, and reaches the end. With the stipulation that we not consider the time of the question, the two possibilities are not mutually exclusive.

The above considerations about the nature of “explanation” lead to various conclusions, but also to various new questions. For example, one commenter suggested that “explanation” is merely subjective. Now as I said there, all experience is subjective experience (what would “objective experience” even mean, except that someone truly had a subjective experience?), including the experience of having an explanation. Nonetheless, the thing experienced is not subjective: the origins that we call explanations objectively exclude the apparent possibilities, or objectively make them less intelligible. The explanation of explanation here, however, provides an answer to what was perhaps the implicit question. Namely, why are we so interested in explanations in the first place, so that the experience of understanding something becomes a particularly special type of experience? Why, as Aristotle puts it, do “all men desire to know,” and why is that desire particularly satisfied by explanations?

In one sense it is sufficient simply to say that understanding is good in itself. Nonetheless, there is something particular about the structure of a human being that makes knowledge good for us, and which makes explanation a particularly desirable form of knowledge. In my employer and employee model of human psychology, I said that “the whole company is functioning well overall when the CEO’s goal of accurate prediction is regularly being achieved.” This very obviously requires knowledge, and explanation is especially beneficial because it excludes alternatives, which reduces uncertainty and therefore tends to make prediction more accurate.

However, my account also raises new questions. If explanation eliminates alternatives, what would happen if everything was explained? We could respond that “explaining everything” is not possible in the first place, but this is probably an inadequate response, because (from the linked argument) we only know that we cannot explain everything all at once, the way the person in the room cannot draw everything at once; we do not know that there is any particular thing that cannot be explained, just as there is no particular aspect of the room that cannot be drawn. So there can still be a question about what would happen if every particular thing in fact has an explanation, even if we cannot know all the explanations at once. In particular, since explanation eliminates alternatives, does the existence of explanations imply that there are not really any alternatives? This would suggest something like Leibniz’s argument that the actual world is the best possible world. It is easy to see that such an idea implies that there was only one “possibility” in the first place: Leibniz’s “best possible world” would be rather “the only possible world,” since the apparent alternatives, given that they would have been worse, were not real alternatives in the first place.

On the other hand, if we suppose that this is not the case, and there are ultimately many possibilities, does this imply the existence of “brute facts,” things that could have been otherwise, but which simply have no explanation? Or at least things that have no complete explanation?

Let the reader understand. I have already implicitly answered these questions. However, I will not link here to the implicit answers because if one finds it unclear when and where this was done, one would probably also find those answers unclear and inconclusive. Of course it is also possible that the reader does see when this was done, but still believes those responses inadequate. In any case, it is possible to provide the answers in a form which is much clearer and more conclusive, but this will likely not be a short or simple project.

Zombies and Ignorance of the Formal Cause

Let’s look again at Robin Hanson’s account of the human mind, considered previously here.

Now what I’ve said so far is usually accepted as uncontroversial, at least when applied to the usual parts of our world, such as rivers, cars, mountains laptops, or ants. But as soon as one claims that all this applies to human minds, suddenly it gets more controversial. People often state things like this:

I am sure that I’m not just a collection of physical parts interacting, because I’m aware that I feel. I know that physical parts interacting just aren’t the kinds of things that can feel by themselves. So even though I have a physical body made of parts, and there are close correlations between my feelings and the states of my body parts, there must be something more than that to me (and others like me). 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 mainly about feelings, not physical parts interacting; we want to know what out there feels so we can know what to care about.

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

What would someone mean by making the original statement that “I know that physical parts interacting just aren’t the kinds of things that can feel by themselves”? If we give this a charitable interpretation, the meaning is that “a collection of physical parts” is something many, and so is not a suitable subject for predicates like “sees” and “understands.” Something that sees is something one, and something that understands is something one.

This however is not Robin’s interpretation. Instead, he understands it to mean that besides the physical parts, there has to be one additional part, namely one which is a part in the same sense of “part”, but which is not physical. And indeed, some tend to think this way. But this of course is not helpful, because the reason a collection of parts is not a suitable subject for seeing or understanding is not because those parts are physical, but because the subject is not something one. And this would remain even if you add a non-physical part or parts. Instead, what is needed to be such a subject is that the subject be something one, namely a living being with the sense of sight, in order to see, or one with the power of reason, for understanding.

What do you need in order to get one such subject from “a collection of parts”? Any additional part, physical or otherwise, will just make the collection bigger; it will not make the subject something one. It is rather the formal cause of a whole that makes the parts one, and this formal cause is not a part in the same sense. It is not yet another part, even a non-physical one.

Reading Robin’s discussion in this light, it is clear that he never even considers formal causes. He does not even ask whether there is such a thing. Rather, he speaks only of material and efficient causes, and appears to be entirely oblivious even to the idea of a formal cause. Thus when asking whether there is anything in addition to the “collection of parts,” he is asking whether there is any additional material cause. And naturally, nothing will have material causes other than the things it is made out of, since “what a thing is made out of” is the very meaning of a material cause.

Likewise, when he says, “Does this other feeling stuff interact with the familiar parts of our world strongly and reliably enough to usually be the actual cause of humans making statements of feeling like this?”, he shows in two ways his ignorance of formal causes. First, by talking about “feeling stuff,” which implies a kind of material cause. Second, when he says, “actual cause of humans making statements” he is evidently speaking about the efficient cause of people producing sounds or written words.

In both cases, formal causality is the relevant causality. There is no “feeling stuff” at all; rather, certain things are things like seeing or understanding, which are unified actions, and these are unified by their forms. Likewise, we can consider the “humans making statements” in two ways; if we simply consider the efficient causes of the sounds, one by one, you might indeed explain them as “simple parts interacting simply.” But they are not actually mere sounds; they are meaningful and express the intention and meaning of a subject. And they have meaning by reason of the forms of the action and of the subject.

In other words, the idea of the philosophical zombie is that the zombie is indeed producing mere sounds. It is not only that the zombie is not conscious, but rather that it really is just interacting parts, and the sounds it produces are just a collection of sounds. We don’t need, then, some complicated method to determine that we are not such zombies. We are by definition not zombies if we say, think, or understanding at all.

The same ignorance of the formal cause is seen in the rest of Robin’s comments:

If yes, this is a remarkably strong interaction, making it quite surprising that physicists 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 measurable with existing equipment. Any interaction not so measurable would have be vastly more complex and context dependent than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will measure such an interaction.

Again, he is asking whether there is some additional part which has some additional efficient causality, and suggesting that this is unlikely. It is indeed unlikely, but irrelevant, because consciousness is not an additional part, but a formal way of being that a thing has. He continues:

But if no, if this interaction isn’t strong enough to explain human claims of feeling, then we have a remarkable coincidence to explain. Somehow this extra feeling stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that feeling 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 feeling 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 feeling stuff actually exists? Such a coincidence seems too remarkable to be believed.

First, there is no “extra feeling stuff.” There is only a way of being, namely in this case being alive and conscious. Second, there is no coincidence. Robin’s supposed coincidence is that “I am conscious” is thought to mean, “I have feeling stuff,” but the feeling stuff is not the efficient cause of my saying that I have it; instead, the efficient cause is said to be simple parts interacting simply.

Again, the mistake here is simply to completely overlook the formal cause. “I am conscious” does not mean that I have any feeling stuff; it says that I am something that perceives. Of course we can modify Robin’s question: what is the efficient cause of my saying that I am conscious? Is it the fact that I actually perceive things, or is it simple parts interacting simply? But if we think of this in relation to form, it is like asking whether the properties of a square follow from squareness, or from the properties of the parts of a square. And it is perfectly obvious that the properties of a square follow both from squareness, and from the properties of the parts of a square, without any coincidence, and without interfering with one another. In the same way, the fact that I perceive things is the efficient cause of my saying that I perceive things. But the only difference between this actual situation and a philosophical zombie is one of form, not of matter; in a corresponding zombie, “simple parts interacting simply” are the cause of its producing sounds, but it neither perceives anything nor asserts that it is conscious, since its words are meaningless.

The same basic issue, namely Robin’s lack of the concept of a formal cause, is responsible for his statements about philosophical zombies:

Carroll inspires me to try to make one point I think worth making, even if it is also ignored. My target is people who think philosophical zombies make sense. Zombies are supposedly just like real people in having the same physical brains, which arose the through the same causal history. The only difference is that while real people really “feel”, zombies do not. But since this state of “feeling” is presumed to have zero causal influence on behavior, zombies act exactly like real people, including being passionate and articulate about claiming they are not zombies. 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. (And which other systems feel as well.)

The one point I want to make is: if zombies are conceivable, then none of us will ever have any more relevant info than we do now about which systems actually feel. Which is pretty much zero info! You will never have any info about whether you ever really felt in the past, or will ever feel in the future. No one part of your brain ever gets any info from any other part of your brain about whether it really feels.

The state of “feeling” is not presumed to have zero causal influence on behavior. It is thought to have precisely a formal influence on behavior. That is, being conscious is why the activity of the conscious person is “saying that they feel” instead of “producing random meaningless sounds that others mistakenly interpret as meaning that they feel.”

Robin is right that philosophical zombies are impossible, however, although not for the reasons that he supposes. The actual reason for this is that it is impossible for a disposed matter to be lacking its corresponding form, and the idea of a zombie is precisely the idea of humanly disposed matter lacking human form.

Regarding his point about “info,” the possession of any information at all is already a proof that one is not a zombie. Since the zombie lacks form, any correlation between one part and another in it is essentially a random material correlation, not one that contains any information. If the correlation is noticed as having any info, then the thing noticing the information, and the information itself, are things which possess form. This argument, as far as it goes, is consistent with Robin’s claim that zombies do not make sense; they do not, but not for the reasons that he posits.

Zeal for Form, But Not According to Knowledge

Some time ago I discussed the question of whether the behavior of a whole should be predictable from the behavior of the parts, without fully resolving it. I promised at the time to revisit the question later, and this is the purpose of the present post.

In the discussion of Robin Hanson’s book Age of Em, we looked briefly at his account of the human mind. Let us look at a more extended portion of his argument about the mind:

There is nothing that we know of that isn’t described well by physics, and everything that physicists know of is well described as many simple parts interacting simply. Parts are localized in space, have interactions localized in time, and interactions effects don’t move in space faster than the speed of light. Simple parts have internal states that can be specified with just a few bits (or qubits), and each part only interacts directly with a few other parts close in space and time. Since each interaction is only between a few bits on a few sides, it must also be simple. Furthermore, all known interactions are mutual in the sense that the state on all sides is influenced by states of the other sides.

For example, ordinary field theories have a limited number of fields at each point in space-time, with each field having a limited number of degrees of freedom. Each field has a few simple interactions with other fields, and with its own space-time derivatives. With limited energy, this latter effect limits how fast a field changes in space and time.

As a second example, ordinary digital electronics is made mostly of simple logic units, each with only a few inputs, a few outputs, and a few bits of internal state. Typically: two inputs, one output, and zero or one bits of state. Interactions between logic units are via simple wires that force the voltage and current to be almost the same at matching ends.

As a third example, cellular automatons are often taken as a clear simple metaphor for typical physical systems. Each such automation has a discrete array of cells, each of which has a few possible states. At discrete time steps, the state of each cell is a simple standard function of the states of that cell and its neighbors at the last time step. The famous “game of life” uses a two dimensional array with one bit per cell.

This basic physics fact, that everything is made of simple parts interacting simply, implies that anything complex, able to represent many different possibilities, is made of many parts. And anything able to manage complex interaction relations is spread across time, constructed via many simple interactions built up over time. So if you look at a disk of a complex movie, you’ll find lots of tiny structures encoding bits. If you look at an organism that survives in a complex environment, you’ll find lots of tiny parts with many non-regular interactions.

Physicists have learned that we only we ever get empirical evidence about the state of things via their interactions with other things. When such interactions the state of one thing create correlations with the state of another, we can use that correlation, together with knowledge of one state, as evidence about the other state. If a feature or state doesn’t influence any interactions with familiar things, we could drop it from our model of the world and get all the same predictions. (Though we might include it anyway for simplicity, so that similar parts have similar features and states.)

Not only do we know that in general everything is made of simple parts interacting simply, for pretty much everything that happens here on Earth we know those parts and interactions in great precise detail. Yes there are still some areas of physics we don’t fully understand, but we also know that those uncertainties have almost nothing to say about ordinary events here on Earth. For humans and their immediate environments on Earth, we know exactly what are all the parts, what states they hold, and all of their simple interactions. Thermodynamics assures us that there can’t be a lot of hidden states around holding many bits that interact with familiar states.

Now it is true that when many simple parts are combined into complex arrangements, it can be very hard to calculate the detailed outcomes they produce. This isn’t because such outcomes aren’t implied by the math, but because it can be hard to calculate what math implies. When we can figure out quantities that are easier to calculate, as long as the parts and interactions we think are going on are in fact the only things going on, then we usually see those quantities just as calculated.

The point of Robin’s argument is to take a particular position in regard to the question we are revisiting in this post: everything that is done by wholes is predictable from the behavior of the parts. The argument is simply a more extended form of a point I made in the earlier post, namely that there is no known case where the behavior of a whole is known not to be predictable in such a way, and many known cases where it is certainly predictable in this way.

The title of the present post of course refers us to this earlier post. In that post I discussed the tendency to set first and second causes in opposition, and noted that the resulting false dichotomy leads to two opposite mistakes, namely the denial of a first cause on one hand, and to the assertion that the first cause does or should work without secondary causes on the other.

In the same way, I say it is a false dichotomy to set the work of form in opposition with the work of matter and disposition. Rather, they produce the same thing, both according to being and according to activity, but in different respects. If this is the case, it will be necessarily true from the nature of things that the behavior of a whole is predictable from the behavior of the parts, but this will happen in a particular way.

I mentioned an example of the same false dichotomy in the post on Robin’s book. Here again is his argument:

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

If yes, this is a remarkably strong interaction, making it quite surprising that physicists 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 measurable with existing equipment. Any interaction not so measurable would have be vastly more complex and context dependent than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will measure such an interaction.

But if no, if this interaction isn’t strong enough to explain human claims of feeling, then we have a remarkable coincidence to explain. Somehow this extra feeling stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that feeling 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 feeling 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 feeling stuff actually exists? Such a coincidence seems too remarkable to be believed.

I am currently awake and conscious, hearing the sounds of my keyboard as I type and the music playing in the background. Robin’s argument is something like this: why did I type the previous sentence? Is it because I am in fact awake and conscious and actually heard these sounds? If in principle it is predictable that I would have typed that, based on the simple interactions of simple parts, that seems to be an entirely different explanation. So either one might be the case or the other, but not both.

We have seen this kind of argument before. C.S. Lewis made this kind of argument when he said that thought must have reasons only, and no causes. Similarly, there is the objection to the existence of God, “But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist.” Just as in those cases we have a false dichotomy between the first cause and secondary causes, and between the final cause and efficient causes, so here we have a false dichotomy between form and matter.

Let us consider this in a simpler case. We earlier discussed the squareness of a square. Suppose someone attempted to apply Robin’s argument to squares. The equivalent argument would say this: all conclusions about squares can be proved from premises about the four lines that make it up and their relationships. So what use is this extra squareness? We might as well assume it does not exist, since it cannot explain anything.

In order to understand this one should consider why we need several kinds of cause in the first place. To assign a cause is just to give the origin of a thing in a way that explains it, while explanation has various aspects. In the linked post, we divided causes into two, namely intrinsic and extrinsic, and then divided each of these into two. But consider what would happen if we did not make the second division. In this case, there would be two causes of a thing: matter subject to form, and agent intending an end. We can see from this how the false dichotomies arise: all the causality of the end must be included in some way in the agent, since the end causes by informing the agent, and all the causality of the form must be included in some way in the matter, since the form causes by informing the matter.

In the case of the square, even the linked post noted that there was an aspect of the square that could not be derived from its properties: namely, the fact that a square is one figure, rather than simply many lines. This is the precise effect of form in general: to make a thing be what it is.

Consider Alexander Pruss’s position on artifacts. He basically asserted that artifacts do not truly exist, on the grounds that they seem to be lacking a formal cause. In this way, he says, they are just a collection of parts, just as someone might suppose that a square is just a collection of lines, and that there is no such thing as squareness. My response there was the same as my response about the square: saying that this is just a collection cannot explain why a square is one figure, nor can the same account explain the fact that artifacts do have a unity of some kind. Just as the denial of squareness would mean the denial of the existence of a unified figure, so the denial of chairness would mean the denial of the existence of chairs. Unlike Sean Carroll, Pruss seems even to recognize that this denial follows from his position, even if he is ambivalent about it at times.

Hanson’s argument about the human mind is actually rather similar to Pruss’s argument about artifacts, and to Carroll’s argument about everything. The question of whether or not the fact that I am actually conscious influences whether I say that I am, is a reference to the idea of a philosophical zombie. Robin discusses this idea more directly in another post:

Carroll inspires me to try to make one point I think worth making, even if it is also ignored. My target is people who think philosophical zombies make sense. Zombies are supposedly just like real people in having the same physical brains, which arose the through the same causal history. The only difference is that while real people really “feel”, zombies do not. But since this state of “feeling” is presumed to have zero causal influence on behavior, zombies act exactly like real people, including being passionate and articulate about claiming they are not zombies. 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. (And which other systems feel as well.)

The one point I want to make is: if zombies are conceivable, then none of us will ever have any more relevant info than we do now about which systems actually feel. Which is pretty much zero info! You will never have any info about whether you ever really felt in the past, or will ever feel in the future. No one part of your brain ever gets any info from any other part of your brain about whether it really feels.

These claims all follow from our very standard and well-established info theory. We get info about things by interacting with them, so that our states become correlated with the states of those things. But by assumption this hypothesized extra “feeling” state never interacts with anything. The actual reason why you feel compelled to assert very confidently that you really do feel has no causal connection with whether you actually do really feel. You would have been just as likely to say it if it were not true. What could possibly be the point of hypothesizing and forming beliefs about states about which one can never get any info?

We noted the unresolved tension in Sean Carroll’s position. The eliminativists are metaphysically correct, he says, but they are mistaken to draw the conclusion that the things of our common experience do not exist. The problem is that given that he accepts the eliminativist metaphysics, he can have no justification for rejecting their conclusions. We can see the same tension in Robin Hanson’s account of consciousness and philosophical zombies. For example, why does he say that they do not “make sense,” rather than asking whether or not they can exist and why or why not?

Let us think about this in more detail. And to see more clearly the issues involved, let us consider a simpler case. Take the four chairs in Pruss’s office. Is it possible that one of them is a zombie?

What would this even mean? In the post on the relationship of form and reality, we noted that asking whether something has a form is very close to the question of whether something is real. I really have two hands, Pruss says, if my hands have forms. And likewise chairs are real chairs if they have the form of a chair, and if they do not, they are not real in the first place, as Pruss argues is the case.

The zombie question about the chair would then be this: is it possible that one of the apparent chairs, physically identical to a real chair, is yet not a real chair, while the three others are real?

We should be able to understand why someone would want to say that the question “does not make sense” here. What would it even be like for one of the chairs not to be a real chair, especially if it is posited to be identical to all of the others? In reality, though, the question does make sense, even if we answer that the thing cannot happen. In this case it might actually be more possible than in other cases, since artifacts are in part informed by human intentions. But possible or not, the question surely makes sense.

Let us consider the case of natural things. Consider the zombie oak tree: it is physically identical to an oak tree, but it is not truly alive. It appears to grow, but this is just the motion of particles. There are three positions someone could hold: no oak trees are zombie oaks, since all are truly alive and grow; all oak trees are zombies, since all are mere collections of particles; and some are alive and grow, while others are zombies, being mere collections of particles.

Note that the question does indeed make sense. It is hard to see why anyone would accept the third position, but if the first and second positions make sense, then the third does as well. It has an intelligible content, even if it is one that we have no good arguments for accepting. The argument that it does not make sense is basically the claim that the first and second positions are not distinct positions: they do not say different things, but the same thing. Thus the the third would “not make sense” insofar as it assumes that the first and second positions are distinct positions.

Why would someone suppose that the first and second positions are not distinct? This is basically Sean Carroll’s position, since he tries to say both that eliminativists are correct about what exists, but incorrect in denying the existence of common sense things like oak trees. It is useful to say, “oak trees are real,” he says, and therefore we will say it, but we do not mean to say something different about reality than the eliminativists who say that “oak trees are not real but mere collections of particles.”

But this is wrong. Carroll’s position is inconsistent in virtually the most direct possible way. Either oak trees are real or they are not; and if they are real, then they are not mere collections of particles. So both the first and second positions are meaningful, and consequently also the third.

The second and third positions are false, however, and the meaningfulness of this becomes especially clear when we speak of the human case. It obviously does make sense to ask whether other human beings are conscious, and this is simply to ask whether their apparent living activities, such as speaking and thinking, are real living activities, or merely apparent ones: perhaps the thing is making sounds, but it is not truly speaking or thinking.

Let us go back to the oak tree for a moment. The zombie oak would be one that is not truly living, but its activities, apparently full of life, are actually lifeless. In order to avoid this possibility, and out of a zeal for form which is not according to knowledge, some assert that the activities of an oak cannot be understood in terms of the activities of the parts. There is a hint of this, perhaps, in this remark by James Chastek:

Consciousness is just the latest field where we are protesting that something constitutes a specific difference from some larger genus, but if it goes the way the others have gone, in fifty years no one will even remember the controversy or bother to give the fig-leaf explanations of it being emergent or reductive. No one will remember that there is a difference to explain. Did anyone notice in tenth-grade biology that life was explained entirely in terms of non-living processes? No. There was nothing to explain since nothing was noticed.

Chastek does not assert that life cannot be “explained entirely in terms of non-living processes,” in the manner of tenth-grade biology, but he perhaps would prefer that it could not be so explained. And the reason for this would be the idea that if everything the living thing does can be explained in terms of the parts, then oak trees are zombies after all.

But this idea is mistaken. Look again at the square: the parts explain everything, except the fact that the figure is one figure, and a square. The form of a square is indeed needed, precisely in order that the thing will actually be a whole and a square.

Likewise with the oak. If an oak tree is made out of parts, then since activity follows being, it should be unsurprising that in some sense its activities themselves will be made out of parts, namely the activities of its parts. But the oak is real, and its activities are real. And just as oaks really exist, so they really live and grow; but just as the living oak has parts which are not alive in themselves, such as elements, so the activity of growth contains partial activities which are not living activities in themselves. What use is the form of an oak, then? It makes the tree really an oak and really alive; and it makes its activities living activities such as growth, rather than being merely a collection of non-living activities.

We can look at human beings in the same way, but I will leave the details of this for another post, since this one is long enough already.

Form and the Goodness of God

In his commentary on the Sentences of Peter Lombard, St. Thomas says:

Loquendo autem de necessitate quae est ex suppositione divini propositi, quo propter benevolentiam suae bonitatis voluit unicuique eam communicare secundum suam capacitatem, necessarium est quod cuilibet materiae praeparatae forma infundatur. Non tamen eodem modo est in omnibus formis; quia formae quae mediantibus secundis agentibus in materia producuntur, necessario in materia disposita recipiuntur necessitate conditionata in comparatione ad Deum, cujus virtute cetera agentia agunt; sed necessitate absoluta per comparationem ad agentia proxima, quae necessitate naturae agunt propter ordinem divinitus eis impositum, quem praeterire non possunt. Formae autem quae immediate a Deo inducuntur, non habent necessitatem absolutam ex parte agentis, sed quaedam ex parte recipientis, sicut in perfectionibus quae sunt de esse naturae, ut est anima rationalis. Formae autem quae non debentur naturae, sicut gratia et virtutes, immediate a Deo productae, nihil habent de necessitate absoluta, sed solum de necessitate ex suppositione divini ordinis, ut dictum est.

Which is, more or less:

But speaking of the necessity which is on the supposition of the divine intention, by which on account of the benevolence of his [God’s] goodness, he wished to share with each thing according to its capacity, it is necessary that form be infused into every prepared matter. But nevertheless not in the same way in all forms; since forms which are produced in matter through the mediation of secondary agents are necessarily received into matter with a conditional necessity in comparison with God, by the power of whom other agents act, but with an absolute necessity in comparison to the proximate agents, which act by necessity of nature on account of the order divinely imposed on them, which they cannot omit. But forms which are immediately imposed by God, do not have an absolute necessity on the part of the agent, but a certain necessity on the part of the recipient, as in perfections which are of the being of nature, as is the rational soul. And forms which are not owed to nature, like grace and the virtues, produced immediately by God, have nothing of absolute necessity, but only of the necessity on the supposition of the divine order, as was said.

St. Thomas’s overall point is that every disposed matter receives its corresponding form, and that this happens on account of the goodness of God. He asserts that there are three ways in which this happens:

(1) With respect to forms produced through secondary causes, the things involved cannot naturally fail to produce the form in disposed matter, although this is taken to be conditional in comparison with God, presumably in the sense that if God wanted things to happen otherwise, they could happen otherwise, just as St. Thomas asserts that in the Eucharist accidents can exist without substance, by the divine will.

This first case seems intended to cover all natural changes, with one exception (we will get to the exception in a few moments.) So for example, according to St. Thomas, if you dispose matter to be a certain color, it will necessarily be that color; if you dispose matter to be living matter, it will necessarily be living; and so on. Just as we saw with lines and squares, properly disposed matter always has the corresponding form.

(2) Second, there are forms that are “immediately imposed by God,” but which have a certain natural necessity on the part of the recipient. He mentions the rational soul as though it were an example here, but in fact it seems to be the only thing which is meant to fall into this category rather than the third category.

This happens because St. Thomas considers the human soul to be something exceptional and unique in nature, as we can see from his discussion of the human soul as subsistent:

I answer that, It must necessarily be allowed that the principle of intellectual operation which we call the soul, is a principle both incorporeal and subsistent. For it is clear that by means of the intellect man can have knowledge of all corporeal things. Now whatever knows certain things cannot have any of them in its own nature; because that which is in it naturally would impede the knowledge of anything else. Thus we observe that a sick man’s tongue being vitiated by a feverish and bitter humor, is insensible to anything sweet, and everything seems bitter to it. Therefore, if the intellectual principle contained the nature of a body it would be unable to know all bodies. Now every body has its own determinate nature. Therefore it is impossible for the intellectual principle to be a body. It is likewise impossible for it to understand by means of a bodily organ; since the determinate nature of that organ would impede knowledge of all bodies; as when a certain determinate color is not only in the pupil of the eye, but also in a glass vase, the liquid in the vase seems to be of that same color.

Therefore the intellectual principle which we call the mind or the intellect has an operation “per se” apart from the body. Now only that which subsists can have an operation “per se.” For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent.

Elsewhere he says that the human soul alone is special in this way. Thus in the next article he specifically denies subsistence in regard to the souls of other animals:

I answer that, The ancient philosophers made no distinction between sense and intellect, and referred both a corporeal principle, as has been said. Plato, however, drew a distinction between intellect and sense; yet he referred both to an incorporeal principle, maintaining that sensing, just as understanding, belongs to the soul as such. From this it follows that even the souls of brute animals are subsistent. But Aristotle held that of the operations of the soul, understanding alone is performed without a corporeal organ. On the other hand, sensation and the consequent operations of the sensitive soul are evidently accompanied with change in the body; thus in the act of vision, the pupil of the eye is affected by a reflection of color: and so with the other senses. Hence it is clear that the sensitive soul has no “per se” operation of its own, and that every operation of the sensitive soul belongs to the composite. Wherefore we conclude that as the souls of brute animals have no “per se” operations they are not subsistent. For the operation of anything follows the mode of its being.

As a result of this special account of the human soul, St. Thomas asserts that natural agents do not have the capacity, considered in themselves, to produce a human soul. Consequently he says that there is not an absolute necessity on the part of the agents, meaning that there is no necessity because there is not even the possibility, considered on the part of the agents in themselves. But he says there is a necessity on the part of the recipient, meaning that nature would be lacking its appropriate perfection if e.g. the union of human seed and egg did not result in a human soul. And on account of the goodness of God, such a lack will never be permitted. Consequently every matter that is disposed to be human, will actually be human, just as in the case of the forms of the first kind.

(3) Finally, there are forms which are not “owed” to nature in the way that other natural forms are, and in the way in which even the human soul is owed. Here St. Thomas speaks of grace and “the virtues,” by which he means supernatural virtues, not natural virtues.

In order to understand this case, we can imagine a situation where we construct many shapes: squares, circles, triangles and so on. We paint all of them white, with one exception: whenever we have squares, we paint them red. In essence, we have invented a rule: we consider squares, and no other shapes, disposed to be red, and we cause them actually to be so.

In our example, there is nothing about being square that would actually make a thing red. But there is a certain order there, imposed by ourselves, whereby being square is effectively a disposition to be red. In a similar way, St. Thomas asserts that there are dispositions that God considers to be dispositions for grace, even though in themselves they would not be sufficient to make a thing have grace, or even to make a thing need grace. But St. Thomas says that on account of the goodness of God, he considers “doing as well as one can” to be the disposition for grace, and thus God always gives grace to one who does their best, even if they are merely doing their best on a natural level.

While it is not the point of this post, it is because of this account of God’s goodness in relation to form and disposed matter that St. Thomas is fundamentally opposed to any kind of rigid understanding of the doctrine of extra ecclesiam nulla salus. According to St. Thomas, whether there is a natural necessity for it or not, every disposed matter receives its appropriate form, on account of the goodness of God.

Matter, Form, and Disposition

Suppose we have four straight lines, each equal in length to the others, each in contact with one of the others at each of its endpoints, and each at right angles to the lines with which it is in contact.

We can see that these lines form a square. And if we consider the square as the boundary formed of the four lines (it would also be possible, and perhaps more common, to consider the bounded area as a square), then the lines are parts and material causes of the square. And those parts cause the whole by having squareness, the formal cause.

What is squareness? Someone might say it is simply the properties described in the first paragraph above. And this is close to the truth, but it is not exactly right. For a square is one figure, and the properties described are many, and insofar as they are many, they do not sufficiently explain the unity of the square. Squareness is rather the shape that a thing has which has those properties; and that shape is one shape, not many shapes.

The properties described, then, are not squareness itself, but can be called the disposition to squareness. By having these properties, the four lines are disposed to have squareness, and consequently to form a square.