STRANGER: There is some part of the other which is opposed to the beautiful?
THEAETETUS: There is.
STRANGER: Shall we say that this has or has not a name?
THEAETETUS: It has; for whatever we call not-beautiful is other than the beautiful, not than something else.
STRANGER: And now tell me another thing.
THEAETETUS: What?
STRANGER: Is the not-beautiful anything but this—an existence parted off from a certain kind of existence, and again from another point of view opposed to an existing something?
THEAETETUS: True.
STRANGER: Then the not-beautiful turns out to be the opposition of being to being?
THEAETETUS: Very true.