Parts and Parmenides

Much of the difficulty of the topic of the previous post simply results from the difficulty of understanding the idea of part and whole. In our original discussion of these concepts, I noted that in order to be a whole, a thing must be itself, but also in a certain way other things which it simply speaking is not.

There is a temptation to say that this is a contradiction: since we admit that the whole is not its part, it cannot be that part in any way, and therefore it cannot satisfy our definition of a whole. And thus it would be impossible to have a whole and parts.

Parmenides attempts to resolve this problem in a simplistic manner, namely by denying the reality of distinction. Since it is impossible for one thing to be distinct from another, it is impossible to for there to be many things which could be made into a whole. There is only one thing, and consequently no need to make anything out of parts.

A more sophisticated and more common solution is to admit the reality of distinction, but to continue to deny the possibility of forming wholes from parts. By confusing the idea of “fundamental” as the primary material cause with the idea of “fundamental” as most real, Sean Carroll accepts this solution.

Both proposed solutions are contrary to common sense, and both effectively deny the reality of all the things of our common experience. Parmenides makes this denial openly, Carroll by implication, although he at least wishes to avoid it.

There is an additional inconsistency in Carroll’s view insofar as we cannot avoid thinking of the universe as a kind of whole. In other words, just as Parmenides wished to say, “there is only one thing,” Carroll wishes to say, “there are only many things.” But this cannot be done: for there cannot be many things, unless those many are in some way one.

Alexander Pruss attempts to formulate a still more sophisticated solution, which to some extent we have already discussed:

Some people are attracted to nihilism about proper parthood: no entity has proper parts. I used to be rather attracted to that myself, but I am now finding that a different thesis fits better with my intuitions: no entity is (fully) grounded. Or to put it positively: only fundamental entities exist.

This has some of the same consequences that nihilism about proper parthood would. For instance, on nihilism about proper parthood, there are no artifacts, since if there were any, they’d have proper parts. But on nihilism about ontological grounding, we can also argue that there are no artifacts, since the existence of an artifact would be grounded in social and physical facts. Moreover, nihilism about ontological grounding implies nihilism about mereological sum: for the existence of a mereological sum would be grounded in the existence of its proper parts. However, nihilism about ontological grounding is compatible with some things having parts–but they have to be things that go beyond their parts, things whose existence is not grounded in the existence and relations of their parts.

Note that he states that he was formerly attracted to the view that “no entity has proper parts.” This would assert, like the views of Parmenides and Sean Carroll, that wholes and parts are impossible. Since this seems too opposed to common sense, he formulates a new view, where it is possible for a thing to have parts, but the thing must “go beyond” its parts in some way. The existence of the whole “is not grounded” in the existence and relations of its parts.

It is not clear to me precisely what he means by grounding here, and his position could be true, if this is understood in some ways, and not true, if it is understood in others. It could be taken in a fairly tautological sense: something with parts is real if it is really one thing, and not merely many things. But we could just as well say that many things cannot exist without being in some way one. And this does not seem to be Pruss’s intended meaning, since he denies the reality of artifacts, even in this text, which would not be necessary on this understanding.

In any case there does seem to be some remaining desire to deny in some way the possibility of whole and part, indicated for example in the statement that “only fundamental entities exist.” Of course if we understand “fundamental” to mean “real,” then the statement is that only real things exist, and this is obviously true. But like in the case of Carroll, it is evident that fundamental here is meant to refer in some way to what things are made from, namely to material causes. The difference is that rather than saying that the fundamental things are particles of some kind, Pruss would say that some fundamental things are particles, while others are human beings and so on.

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.

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.

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.

All Things are Water

In book I of his Metaphysics, Aristotle comments on earlier opinions about the first causes:

Evidently we have to acquire knowledge of the original causes (for we say we know each thing only when we think we recognize its first cause), and causes are spoken of in four senses. In one of these we mean the substance, i.e. the essence (for the ‘why’ is reducible finally to the definition, and the ultimate ‘why’ is a cause and principle); in another the matter or substratum, in a third the source of the change, and in a fourth the cause opposed to this, the purpose and the good (for this is the end of all generation and change). We have studied these causes sufficiently in our work on nature, but yet let us call to our aid those who have attacked the investigation of being and philosophized about reality before us. For obviously they too speak of certain principles and causes; to go over their views, then, will be of profit to the present inquiry, for we shall either find another kind of cause, or be more convinced of the correctness of those which we now maintain.

Of the first philosophers, then, most thought the principles which were of the nature of matter were the only principles of all things. That of which all things that are consist, the first from which they come to be, the last into which they are resolved (the substance remaining, but changing in its modifications), this they say is the element and this the principle of things, and therefore they think nothing is either generated or destroyed, since this sort of entity is always conserved, as we say Socrates neither comes to be absolutely when he comes to be beautiful or musical, nor ceases to be when loses these characteristics, because the substratum, Socrates himself remains. just so they say nothing else comes to be or ceases to be; for there must be some entity-either one or more than one-from which all other things come to be, it being conserved.

Yet they do not all agree as to the number and the nature of these principles. Thales, the founder of this type of philosophy, says the principle is water (for which reason he declared that the earth rests on water), getting the notion perhaps from seeing that the nutriment of all things is moist, and that heat itself is generated from the moist and kept alive by it (and that from which they come to be is a principle of all things). He got his notion from this fact, and from the fact that the seeds of all things have a moist nature, and that water is the origin of the nature of moist things.

Some think that even the ancients who lived long before the present generation, and first framed accounts of the gods, had a similar view of nature; for they made Ocean and Tethys the parents of creation, and described the oath of the gods as being by water, to which they give the name of Styx; for what is oldest is most honourable, and the most honourable thing is that by which one swears. It may perhaps be uncertain whether this opinion about nature is primitive and ancient, but Thales at any rate is said to have declared himself thus about the first cause.

It is possibly for polemical motives that Aristotle portrays Thales as asserting that water alone is the principle of all things, to the exclusion of other kinds of cause besides the material cause. That is, most materialists, ancient and modern, do not believe that matter is the sole principle of reality. They may think it is the most important principle, but they recognize that other principles are involved, much as Lucretius recognizes that his atoms alone are insufficient to explain the world, but he must add something:

We wish thee also well aware of this:
The atoms, as their own weight bears them down
Plumb through the void, at scarce determined times,
In scarce determined places, from their course
Decline a little- call it, so to speak,
Mere changed trend. For were it not their wont
Thuswise to swerve, down would they fall, each one,
Like drops of rain, through the unbottomed void;
And then collisions ne’er could be nor blows
Among the primal elements; and thus
Nature would never have created aught.

We can understand however that even if Aristotle’s account may not be a completely accurate account of Thales’s opinions, Aristotle likely has a charitable motive for his presentation, namely the education of the reader, as by beginning by discussing the position that matter alone is the first cause, it becomes easier to see the necessity of other principles. And it is also possible that Thales did not mention any other principles simply because his interest was in the material principle, rather than from the wish to deny other principles.

There is some probability to the opinion, mentioned by Aristotle, that Thales’s idea about water had ancient predecessors. For example, there may be something like this in Genesis 1:

In the beginning when God created the heavens and the earth, the earth was a formless void and darkness covered the face of the deep, while a wind from God swept over the face of the waters. Then God said, “Let there be light”; and there was light. And God saw that the light was good; and God separated the light from the darkness. God called the light Day, and the darkness he called Night. And there was evening and there was morning, the first day.

And God said, “Let there be a dome in the midst of the waters, and let it separate the waters from the waters.” So God made the dome and separated the waters that were under the dome from the waters that were above the dome. And it was so. God called the dome Sky. And there was evening and there was morning, the second day.

And God said, “Let the waters under the sky be gathered together into one place, and let the dry land appear.” And it was so. God called the dry land Earth, and the waters that were gathered together he called Seas. And God saw that it was good.

The text speaks of a number of principles, including God, and formless matter. But the formless matter is virtually identified with water; even when the earth is a “formless void,” there is still a “deep”, and there is still a “face of the waters.” And God makes the world by divisions in the waters, creating first sky and world, and then creating dry land by limiting the lower waters.

We can ask whether Thales was right in several different ways:

First, was he right if he is understood as Aristotle understands him? In this way, his position would involve denying all principles other than material principles. And in this way Thales was wrong, since there are other principles.

Second, was he right if he is understood in contrast with other materialist philosophers such as Anaximenes, who said that all things are made of air? We can see that there is a certain difficulty in such a supposition from the beginning. For if there is only one material principle of all things, why call it “water” or “air” in particular? If water contains nothing but the first material principle, and air contains nothing but the first material principle, why is one of them identified with the principle rather than the other?

Nonetheless, we can understand the claim to be something like, “Water is the most basic and natural form of the first material principle.” In this case, what it means to be the most basic and natural would be a matter of investigation, but there is nothing impossible about it in principle. But if we understand it in this way, Thales’s position (along with that of Anaximenes and others) is refuted by modern science, since water is known to be made of other more basic things, namely oxygen and hydrogen.

But we can ask whether Thales and Anaximenes were both right in a third way, a more generic way. If we break composite material things down into their parts, and their parts into their parts, and so on, will we always arrive at one basic material “stuff” which all other things are made out of?

This would necessarily be different from the prime matter of Aristotle, because this matter is understood to be completely formless. So while it may be part of a substance along with substantial form, it is not a part in the way that an arm is a part of a human being, or in the way that oxygen is part of water. A part in the latter sense already has some actuality; an arm has a certain shape even apart from being a part of a human being, and oxygen has qualities that it has even apart from water, while prime matter has no actuality whatsoever.

Since every order of causes comes to a first cause, the same will be true if we follow the order of material causality found by asking, “What parts is this made out of?” This cannot be refuted even if it turns out that material things are infinitely divisible, because it will not actually be true that anything is made out of an infinite number of parts. If we say, “this is made out of two halves, and the halves out of more halves, and so on,” this is not an explanation at all, as was pointed out in the post linked above, and so it cannot be a true account of why the thing is as it is. It may be that the thing is potentially divisible in those ways; but it is not actually made out of those parts. Instead, we are asking what we will arrive at if we look at the material composition of things, looking only for things with some actuality, and stopping when we find something which is not made up of other things in this way.

We made a strong argument that there only one first efficient cause. But we cannot duplicate that argument to show that there must be only one first material part of things, since the first efficient cause could be an adequate explanation of two or more first material causes. The theory of the four (or five) elements is an explanation like this. The first material parts are thought be four or five, according to this account, and in this way Thales would have been mistaken.

We can see some motivation for holding such a position. If there is fundamentally only one kind of “stuff,” why do we see various things in the world, such as plants and animals, rocks, chairs, and people? An account with a number elements can say that they form various things by being combined in various proportions and ways, while it is not evident how this question can be answered, if there is only one element.

Nonetheless, this does not really refute the position that there is fundamentally a single material element. If that element can exist in various ways, then it would be possible to explain how it could be used to form more complex substances. It is true that this would still leave something to be explained, namely the nature of those various ways that the element can exist, and how and why they come to be.

The position is neither refuted nor established by modern science. The Standard Model of particle physics contains many elementary particles, but in any case it is not thought to be a complete theory of physics.

Considerations of simplicity would favor the position of Thales. Other things being equal, it should be thought that a theory with a single element is more likely than one with ten elements; one with ten more likely than one with a hundred, and so on. Nonetheless, there does not seem to be any proof of Thales’s general position, nor any refutation of it. But one way or another, there will be one or more simplest material parts that everything else is made out of.