The Republic by Plato Part 5 Page 106

The individual objects of which I am speaking are also a riddle, and have a double sense: nor can you fix them in your mind, either as being or not-being, or both, or neither.

Then what will you do with them? I said. Can they have a better place than between being and not-being? For they are clearly not in greater darkness or negation than not-being, or more full of light and existence than being.

That is quite true, he said.

Thus then we seem to have discovered that the many ideas which the multitude entertain about the beautiful and about all other things are tossing about in some region which is half-way between pure being and pure not-being?

We have.

Yes; and we had before agreed