The theory, then, that other things participate in the ideas by resemblance, has to be given up, and some other mode of participation devised?
It would seem so.
Do you see then, Socrates, how great is the difficulty of affirming the ideas to be absolute?
Yes, indeed.
And, further, let me say that as yet you only understand a small part of the difficulty which is involved if you make of each thing a single idea, parting it off from other things.
What difficulty? he said.
There are many, but the greatest of all is this:—If an opponent argues that these ideas, being such as we say they ought to be, must remain unknown, no one can prove to him that he is wrong, unless he who denies their existence be a man of great ability and knowledge, and is willing to follow a long and laborious demonstration; he will remain unconvinced, and still insist that they cannot be known.
What do you mean, Parmenides? said Socrates.
In the first place, I think, Socrates, that you, or any one who maintains the existence of absolute essences, will admit that they cannot exist in us.
No, said Socrates; for then they would be no longer absolute.