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

by Peter S. Adamson

What would it even mean for something to be good, but not for you, or for anyone in particular?

why pay to go to the doctor if you are just as good a measure as the doctor is?

Whenever you’re presented with a bold new theory, ask whether the theory is consistent with itself.

Socrates suggests that Protagoras’ relativism doctrine is self-refuting. For, even if Protagoras agrees with the doctrine, Socrates does not. Thus it will be true for Socrates that Protagoras’ doctrine is false. Indeed, since this follows from Protagoras’ doctrine, it will even be true for Protagoras that for Socrates the doctrine is false (171b). Thus Protagoras is bound by his own doctrine to admit that his doctrine is false.

Perhaps knowledge is having a true belief (178b). After all, when I know something I have a belief about it, and it obviously can’t be a false belief. So why not say I know something when I have a true belief about it?

Some sophists suggested that it is impossible to say or believe anything false—in which case everything is just a matter of persuasion.

reminiscent of Meno’s paradox. It goes like this: either I know something or I don’t. If I do know it, then obviously my knowledge will prevent me from making mistakes. But if I don’t know the thing in question, then my ignorance will prevent me from even thinking about it; you don’t

have false beliefs about people you have never even heard of, for instance. So I won’t be able to make a mistake then either. In other words, I’ll either have perfect knowledge of each thing or no knowledge of it at all, and in neither case will I get things wrong. Therefore, it’s impossible to make a mistake, to believe anything false.

First, he says, imagine that your memory is like a wax tablet—

When you perceive something, that’s like a stamp making an impression in the wax of your mind

nice image of how memory works, really. Now for false judgment: that would happen when there is a mismatch between something you perceive and an existing impression in the wax of your memory

the characters realize that even if it works for cases of mistaken identity in perception, there are many cases of false judgment where it will not help. For instance, what is going on when I add seven and five and get eleven

Imagine, he says, that your soul is like an aviary, a birdcage, with lots of birds flying around in it, each of which represents a piece of knowledge

What happens when you add five to seven and get eleven is that you reach into your aviary and pull out the eleven bird instead of the twelve bird (199b). Again, your knowledge of eleven actually enables you to make the mistake,

Unfortunately, Socrates and Theaetetus decide that this model too is problematic. It means that when you make a mistake, it is precisely by virtue of knowing that you get things wrong

Theaetetus still feels—and today’s epistemologists tend to agree—that knowledge must have something to do with

true belief. Maybe knowledge is true belief and something else as well,

first dialogue to set out the theory of Forms.

Even in the Phaedo the main topic of the dialogue is not Forms, but the immortality of soul.

they seem to presuppose some kind of dualism as a basis for their discussion. By “dualism,” I mean they assume that the soul is one thing and the body another.

Socrates’ task, then, is to show that the soul is not just distinct from the body, but capable of surviving independently from the body. Along the way, he will show that it is indeed immaterial, invisible, indivisible—all the things we expect a Platonic dualist to believe about the soul.

obviously the soul can exist without the body, since it used to do so. Furthermore, the soul must be akin to the things it knew before birth. This is the cue for the Forms to make their entrance. What we knew before birth and now recollect are things like “the beautiful itself” and “the equal itself,” or as we would usually put it when talking about Plato, “the Form of Beauty” and “the Form of Equal.” These are not physical objects but the natures of which beautiful or equal physical objects partake. So, we already have another way to show the soul’s independence of body, the so-called “affinity argument.” This argument assumes that the soul must be akin to whatever it knows.1 Since these things are eternal and immaterial, the soul too is eternal and immaterial.

“compresence of opposites.”4 The basic idea is that the things in the world around us often have contradictory features, which especially emerge when we are comparing one thing to another. Things may be in one respect equal, in another unequal; in one respect beautiful, in another not beautiful; in one respect good, in another bad.

equality itself and beauty itself must be somehow separate from the sticks and the women, and we must be judging the sticks and the women by looking to an absolute standard of equality and beauty. When we do this, the Forms are the standard by which we judge. So this, along with the theory of recollection, introduces a further reason to believe in Forms: they are standards of judgment, and thus play a crucial role in our knowledge.

Forms not only play a role in Plato’s theory of knowledge (his epistemology). They also play a role in his metaphysics, or to be more specific, his understanding of causation.

His idea here is that the Form of Equal somehow causes equal things like sticks to be equal, while the Form of Bea...

The examples show what Plato expects from a causal explanation. Whether we try to explain the cosmos or why Socrates is sitting in jail, we should select a cause which must give rise to the effect we’re trying to explain. The presence of the true cause shouldn’t be compatible with other possible outcomes.

To oversimplify a bit, it boils down to the following: the cause of, say, largeness should not be small, nor should it be able to cause smallness. Likewise, the cause of equality should not be unequal, and should never cause inequality. Now, Forms seem to satisfy this demand admirably. If things are

equal precisely because they resemble the Form of Equal, it stands to reason both that the Form of Equal is not going to be unequal, and that the Form of Equal never causes anything to be unequal. But if the Form of Equal doesn’t cause things to be unequal, what does? Well, maybe there’s a Form of Unequal too, or maybe things are just unequal because they fail to be perfectly like the Form of Equal, the way your friend’s portrait isn’t perfectly like your friend.

each Form exemplifies itself.

someone who knew the Form of Beauty would know exactly what it means to be beautiful. They would, after all, understand the nature of beauty itself. So they would be able to explain exactly what it is for Helen to be beautiful, and perhaps also why Helen is not beautiful compared to a goddess.

although the Forms may be safe and simple-minded causes, they will be better than at least some clever causes because of their universal application.

what is the soul, if it is not a cause of being alive? But if it is a proper cause, one that satisfies Plato’s demands, then the soul will have to be only alive, not dead—just the way that, in order for snow to be a proper cause of cold, it has to be only cold and not hot.

The soul will have to be permanently alive by its very nature

as a proper cause of life, the soul is by nature immune to death.

Forms help Plato with at least three interconnected problems. First, they give him appropriate objects of knowledge—when we recollect, it will be Forms we are recollecting. Second, Forms are free of the compresence of opposites: the equal things we experience are actually both equal and unequal, but the Form of Equal is not unequal in any way. Third, Forms will be proper and universal causes of features like equality and beauty.

in other dialogues Plato suggests that things in the physical world are constantly changing. Forms allow him to say that some things, at least, are stable and unchanging—a way of avoiding the total-flux doctrine he ascribes to Heraclitus.

Plato was plagued by a whole range of philosophical problems, and he repeatedly found that Forms could help him solve those problems. He was driven by the need to solve philosophical difficulties, not the desire to defend a doctrine for its own sake.

Now the Phaedo, and especially its affinity argument, seem to suggest that the soul is a lot like a Form. So if Socrates is his soul, he will be immaterial, indivisible, immortal.

Harmony in the soul would be nothing less than justice—

It takes in not only political philosophy, but also moral psychology, metaphysics, epistemology, and aesthetics.

He argues that political rule must look to the benefit of the ruled, not that of the ruler—just as the art of medicine looks to the benefit of the patient, not the doctor

We would all gladly be cruel to one another, to take what we can and make others suffer what they must. But we agree not to, because a situation in which everyone is trying to harm everyone winds up being bad for most people most of the time. This is reminiscent of later accounts of morality or political institutions which we call “contract theories.”

This, then, is the task set for Socrates in the Republic: to show that justice is more choiceworthy than injustice, precisely because it is more advantageous.

Socrates introduces this parallel

between soul and city

Unless we’re using the word “justice” in two completely unrelated ways, Socrates must be right that political justice and individual justice have something in common.

if Socrates can discover parallel features and structures in both the soul and the city, then his strategy will show itself to be a good one.

when both Plato and Aristotle talk about political constitutions they normally have in mind

the workings of a polis, a single city, and not an alliance of multiple cities