Of not-being, ignorance was assumed to be the necessary correlative; of being, knowledge?

True, he said.

Then opinion is not concerned either with being or with not-being?

Not with either.

And can therefore neither be ignorance nor knowledge?

That seems to be true.

But is opinion to be sought without and beyond either of them, in a greater clearness than knowledge, or in a greater darkness than ignorance?

In neither.

Then I suppose that opinion appears to you to be darker than knowledge, but lighter than ignorance?

Both; and in no small degree.