Theaetetus : Yes.
Soc: But the being (ousia ) of them, and that they are, and their oppositeness to one another, and again the being of the oppositeness, the soul, by going over and comparing them to one another, will try to determine for us by itself.
Soc: So some things are there for man and beast (theria) to perceive by nature as soon as they are born, all the affections (pathemata) which reach the soul through the body. But calculations (analogismata ) concerning these things, as regards their being (ousia) and their benefit, come to those to whom (hois an) they come with difficulty and over time, and with much effort and education (paideia )?
Soc: So is it possible for someone who does not even find being, to find truth ?
Soc: And will anyone ever know a thing if he does not find its truth?
Theaet: Of course not, Socrates.
Soc: Then knowledge is not in the affections, but in the reasoning (sullogismos) about them. For it is here, so it seems, that it is possible to grasp being and truth, not there.
Soc: So do you call the two cases the same, when they have such great differences?
Theaet: That would not be right.
Soc: What name do you give to the one case - seeing, hearing, smelling, feeling cold, feeling warm?
Theaet: I call it perceiving. What else?
Soc: Then taken together you call it all perception?
Soc: Perception has no share in grasping truth, since it has no share in grasping being (ousia).
Theaet: Indeed not.
Soc: Then it has no share in knowledge.
Soc: Then perception and knowledge could never be the same thing, Theaetetus.
Theaet: Evidently not, Socrates. Now above all it has become absolutely clear that knowledge is something other than perception.
Soc: But we began discussing not to find out what knowledge is not, but what it is. Nonetheless, we have at least progressed far enough not to seek it at all in perception, but in the name of whatever the soul has, when it is occupied by itself concerning beings.
Theaet: Yes, and I think, Socrates, that is called opining (doxazein ).