and yet another cunundrum...

But may not the ideas, asked Socrates, be thoughts only, and have no proper existence except in our minds, Parmenides? For in that case each idea may still be one, and not experience this infinite multiplication.

And can there be individual thoughts which are thoughts of nothing?
Impossible, he said.
The thought must be of something?
Yes.
Of something which is or which is not?
Of something which is.
Must it not be of a single something, which the thought recognizes as attaching to all, being a single form or nature?

Yes.
And will not the something which is apprehended as one and the same in all, be an idea?

From that, again, there is no escape.
Then, said Parmenides, if you say that everything else participates in the ideas, must you not say either that everything is made up of thoughts, and that all things think; or that they are thoughts but have no thought?

The latter view, Parmenides, is no more rational than the previous one. In my opinion, the ideas are, as it were, patterns fixed in nature, and other things are like them, and resemblances of them-what is meant by the participation of other things in the ideas, is really assimilation to them.

But if, said he, the individual is like the idea, must not the idea also be like the individual, in so far as the individual is a resemblance of the idea? That which is like, cannot be conceived of as other than the like of like.

Impossible.
And when two things are alike, must they not partake of the same idea?

They must.
And will not that of which the two partake, and which makes them alike, be the idea itself?

Certainly.
Then the idea cannot be like the individual, or the individual like the idea; for if they are alike, some further idea of likeness will always be coming to light, and if that be like anything else, another; and new ideas will be always arising, if the idea resembles that which partakes of it?

Parmenides, Plato, 370 B.C.E.

...ideas = something?