Plato's Parmenides IV: The Setup

After the great difficulties are raised, Socrates admits that his idea of Forms seems hard to defend. Parmenides agrees that it is very hard to defend, but in terms that strongly suggest that he nevertheless believes it must be right:

These, Socrates, said Parmenides, are a few, and only a few of the

difficulties in which we are involved if ideas really are and we determine

each one of them to be an absolute unity. He who hears what may be

said against them will deny the very existence of them-and even if

they do exist, he will say that they must of necessity be unknown

to man; and he will seem to have reason on his side, and as we were

remarking just now, will be very difficult to convince; a man must

be gifted with very considerable ability before he can learn that

everything has a class and an absolute essence; and still more remarkable

will he be who discovers all these things for himself, and having

thoroughly investigated them is able to teach them to others.

I agree with you, Parmenides, said Socrates; and what you say is very

much to my mind. 

And yet, Socrates, said Parmenides, if a man, fixing his attention

on these and the like difficulties, does away with ideas of things

and will not admit that every individual thing has its own determinate

idea which is always one and the same, he will have nothing on which

his mind can rest; and so he will utterly destroy the power of reasoning,

as you seem to me to have particularly noted. 

Parmenides is suggesting that, without the Forms as at least objects of thought, we cannot reason at all. He's also telling us something about the character of a Form: it is characterized by an essence, which is absolute and unitary. Not just some things of especially high and noble character must have Forms, but anything at all. 

Now we still have the difficulty of understanding whether these Forms are metaphysical or psychological. Parmenides' defense of them is that we need them to think; and if that is true, it is possible that the world doesn't have Forms in it, but rather that they are the way that our minds work. A thing then doesn't have an essence, but is assigned one by us. In this way, everything becomes an artifact, in a way: the thing in the world is not, but the thing as it exists in our mind is an artifact that we have made and assigned a purpose, our thought an artifact just as surely as if we had built a fork out of wood. We made the thing out of raw materials we found in the world, and assigned it a purpose to serve us. 

In that case, then, telos is real enough; but all the telos is human-made, and not inherent in the world. (This is roughly the pre-Socratic philosopher Protagoras' position: "Man is the measure of all things," as it is often given.)

Aristotle will not believe this; his assigning Form as not-separate from the things means that the form really is in the thing. We learn the form by examining the things; our minds grasp it from grappling with the things we encounter. Aristotle's Form is metaphysical, and also physical (but not material). Plato's, as presented in the Republic, is metaphysical but not physical. Parmenides isn't being clear about what he takes the nature of the Forms to be.

Socrates confesses that he has no idea how to proceed under the circumstances. Parmenides tells him this is because he is young, and as yet untrained in rhetoric and debate. If he developed skills in this kind of discourse, it would help him work out his philosophical ideas in a way that he is not ready to do yet.

Socrates asks him how to do this, and Parmenides gives a response he surely meant to be helpful.

I mean, for example, that in the case of this very hypothesis of Zeno's

about the many, you should inquire not only what will be the consequences

to the many in relation to themselves and to the one, and to the one

in relation to itself and the many, on the hypothesis of the being

of the many, but also what will be the consequences to the one and

the many in their relation to themselves and to each other, on the

opposite hypothesis. Or, again, if likeness is or is not, what will

be the consequences in either of these cases to the subjects of the

hypothesis, and to other things, in relation both to themselves and

to one another, and so of unlikeness; and the same holds good of motion

and rest, of generation and destruction, and even of being and not-being.

In a word, when you suppose anything to be or not to be, or to be

in any way affected, you must look at the consequences in relation

to the thing itself, and to any other things which you choose-to each

of them singly, to more than one, and to all; and so of other things,

you must look at them in relation to themselves and to anything else

which you suppose either to be or not to be, if you would train yourself

perfectly and see the real truth. 

Socrates finds this answer as mystifying as most readers do when they first encounter it. He asks for a practical example to help him understand how this process is supposed to work.

That, Parmenides, is a tremendous business of which you speak, and

I do not quite understand you; will you take some hypothesis and go

through the steps?-then I shall apprehend you better. 

That, Socrates, is a serious task to impose on a man of my years.

Nevertheless, that will be the business of the next part. Zeno and others present join in the request to hear Parmenides walk through an example at length, so that they can better understand how to perform this sort of inquiry. 

UPDATE: If your response to reading Parmenides' answer was similar to this, don't feel bad. It's perfectly normal.