Classical Philosophy (A History of Philosophy Without Any Gaps #1)

by Peter S. Adamson

Aristotle calls metaphysics “first philosophy,” “first” not because it is the first one you would study, but because it is the most fundamental philosophical inquiry. He tells us that what metaphysics studies is being. In other words, it studies whatever there is, insofar as it is. This means that many of the traditional problems of philosophy are metaphysical problems: does God exist? Does the human soul exist? Does anything exist apart from physical

bodies? Other topics, like the problem of free will, are usually taken to belong to metaphysics even if they also relate to ethics.

Parmenides, was the first philosopher who we can say had a clear interest in metaphysics, the study of b...

399 BC, the death of Socrates.

Parmenides was strongly identified with his city of Elea, and his followers were often called the “Eleatics.”

Parmenides claims: that reality

itself is one.1 Nothing ever changes or moves. Multiplicity of every sort is an illusion, whether it be the multiplicity of different objects, different colors, or different events happening at different times.

relentless chain of argument that proceeds on the basis of pure reason, rather than ob...

contrast to Heraclitus, who in some of his fragments emphasizes that he is using his eyes and ears to observe the world and to learn the laws that govern that world. But Parmenides and Heraclitus do agree about one thing: everyone else apart from them is completely confused, unaware of the nature of reality.

In the first half we are given the so-called “way of truth”: Parmenides’ arguments for the unity of being. In the second part, the so-called “way of opinion,” we get a cosmology very similar to what we find in the earlier Pre-Socratics from Ionia.

He seems to tell us: if you are going to reject the way of truth and believe something false, then at least believe the falsehoods I offer in the way of opinion.

The primary message of Parmenides’ poem, though, is that we should not trust the senses, but follow philosophical argument wherever it leads.

distinction between two possible paths of inquiry: either “is, and must be” or “isn’t, and can’t be” (§291). The second path is rejected, because it involves trying to think about what is not: non-being is not something we can think or speak about meaningfully. There is actually a third path, mentioned a little later on, which is even worse: according to this path, we say both “is” and “is not.” This has the same problem that we would need to grasp non-being, but in addition leads to a contradiction: both is and is not.

Parmenides points out that being cannot begin to be. After all, it would have to start being after there is no being—but non-being is something we promised not to contemplate (§296). Nor can being be destroyed, for the same reason: it would

have to become non-being (§298). Parmenides infers from this that change is impossible. If there were change, whatever changes would have to go from non-being to being, or being to non-being. Since in either direction we would have the involvement of non-being, this is impossible.

Parmenides gives a further argument for the unity of being at one and the same time. He points out that if being were divided up, it would need to have gaps or divisions in it. These gaps or divisions would, of course, consist of non-being, because they are different from being. So being is also continuous (§297). Any part of it will be just the same as any other part.

idea that being is spherical as a kind of metaphor: maybe the idea is to emphasize that it is determinate because we can think and reason and talk about it successfully.

Being must be perfect, because if it were not it would lack something it could have: and in that case it would contain some kind of non-being, namely the absence of whatever it is lacking.

Parmenides does represent something new. He tries to settle an abstract philosophical issue—the nature of being itself—with an explicit and complex deductive argument.

Zeno of Elea,

Zeno is renowned for the paradoxes he invented in support of Parmenides’ theory that being cannot change or be more than one.

“paradox”

if something is para doxon it is contrary to our beliefs.

Paradoxes are a great way to introduce people to philosophy, because they force us

to think hard about things we normally take for granted.

we have to assume that the paradox is meant to be resolved in one way or another.

Parmenides argued positively, starting out from first principles—in particular, that one can speak and think only about being but never non-being. From this principle he established that being is unchanging and eternal, a perfectly balanced sphere. Zeno takes a different approach, which is more destructive. With his Dichotomy paradox he tries to show us that the concept of motion is itself beset by contradiction.

First, let’s return to the Dichotomy paradox. Here it is again, without the tennis-court: whenever you move from A to B, you have to move to C, the point halfway between A and B; to do that, you have to move to D which is halfway between A and C; and so on. There will be an infinite number of such points, meaning that to move from A to B you have to perform an infinite number of tasks, which is impossible. Or, to put it as Aristotle does when he relates the paradox (§320), you have to come into contact with infinitely many things (namely the halfway points). But why is this impossible? It’s either because you only have a finite time to visit all these points, or simply because no one can do an infinite number of things.

Aristotle offers what I think is a more relevant response to Zeno (Physics 233a). He says that one can divide the time needed to move from A to B right along with the distance from A to B. For instance, if it takes you twenty seconds to get from A to B it will take ten seconds to get halfway there, five seconds to get a quarter of the way there, and so on. It’s simply a mistake on Zeno’s

part to think that one needs an infinite amount of time to visit this infinite number of points, because the divisions will apply to both the time and the distance. This response, though, assumes that Zeno was worried about the motion taking an infinite amount of time. But perhaps his point was rather that it is impossible to perform an infinite number of partial motions in the finite amount of time it takes to perform the whole motion. In that case, Aristotle’s response does not really solve the paradox.

Zeno’s paradoxes try to persuade us that if we assume that more than one thing exists, the results are just as bad.

Melissus of Samos.

Melissus follows the method of Parmenides rather than Zeno. That is, he argues positively that all being is unchanging and one, instead of inventing paradoxes to undermine motion and multiplicity.

Melissus denies that being has any limits at all. After all, if it had limits there would have to be non-being beyond those limits, and there is no such thing as non-being. Thus he calls being “unlimited” or “infinite”: it’s the revenge of

Anaximander’s principle, the apeiron.

argument against the possibility of motion (§534). Again, he starts by ruling out non-being. In this case, the sort of non-being he discusses is emptiness: there cannot be a place with nothing in it, again because there is no such thing as nothing. To put it another way, void is impossible. Now Melissus points out that if there is no void, then that will make motion impossible. After all, there will be no empty place for anything to move into.

anyone who wants to defend the common-sense idea that motion does exist has two possible responses. One would be to agree that there is no void, but insist that there is motion anyway: whenever one thing moves, something else is displaced.

The other response would be to say that, except in the London Underground at rush hour, no place is totally full: there is indeed void.

atoms. By now I hardly need to tell you where the word “atom” comes from. It’s ancient Greek again: tomein means “to cut,” and atoma means quite literally “uncuttables,” In other words, atoms are things that cannot be divided into smaller parts. Not because you don’t have a sharp enough knife, but because they are by their nature indivisible.

the atomism put forward by the fifth-century BC thinkers Leucippus and Democritus was reached by a process of abstract reasoning.

The atomists stop Zeno in his tracks, by assuming that if one keeps dividing and dividing, one will eventually hit bedrock.

This is only one side of the atomists’ picture of the cosmos. The other side, however, doesn’t exist. It’s the nothingness

in which the atoms move around, in other words, vacuum or void. Here, the atomists were reacting to Melissus’ argument that motion is impossible: for something to move it must move into an empty place, but an empty place is nothing, and there is no such thing as nothing. The atomists hijack Melissus’ train of thought and drive it in the other direction. Since we can plainly see that motion is possible, there must be such a thing as nothingness, in which things are moving (§545). This nothingness is the void.

Leucippus

it’s not easy to say where Leucippus stops and Democritus starts. In the ancient sources many of the atomist doctrines are just ascribed indiscriminately to both of them. Democritus’ interests seem to have been considerably wider, though, and for him we have fragments on ethics as well as atomism. Another thing that seems to be distinctive about Democritus, and which I’ll come back to, is that he draws strikingly skeptical conclusions from his atomic theory.

There is an infinite number of atoms (§557). This is crucially important for the atomists, and shows again how they are responding to the Eleatics, and especially

Melissus. For Melissus, being was one and infinite; for the atomists, being is many and infinite. The difference, as I mentioned already, is that the atomists have integrated void, or non-being, into their world picture.

But why do the atoms have to be infinite? Couldn’t there be, say, exactly ten billion atoms bouncing around in an infinite emptiness? In answer to this, the ancient atomists could invoke a rule which is sometimes called the principle of sufficient reason. It states that there has to be some good reason or explanation for each feature of the universe. In the present case, atoms m...

At the level of the whole cosmos, what happens is that huge groups of atoms start to swirl around in a kind of vortex. The heavier and bigger atoms tend to bunch towards the middle and the lighter atoms tend to move to the outside. The former make up the earthy and moist bodies of the earthly world, while the latter turn into the fiery heavens.

there is an infinite number of worlds (§565). Those worlds exhibit every possible combination of atoms.