Stranger: Let us now go to the friends of ideas; of their opinions, too, you shall be the interpreter.
Theaetetus: I will.
Stranger: To them we say—You would distinguish essence from generation?
Theaetetus: “Yes,” they reply.
Stranger: And you would allow that we participate in generation with the body, and through perception, but we participate with the soul through thought in true essence; and essence you would affirm to be always the same and immutable, whereas generation or becoming varies?
Theaetetus: Yes; that is what we should affirm.
Stranger: Well, fair sirs, we say to them, what is this participation, which you assert of both? Do you agree with our recent definition?
Theaetetus: What definition?
Stranger: We said that being was an active or passive energy, arising out of a certain power which proceeds from elements meeting with one another. Perhaps your ears, Theaetetus, may fail to catch their answer, which I recognize because I have been accustomed to hear it.
Theaetetus: And what is their answer?
Stranger: They deny the truth of what we were just now saying to the aborigines about existence.
Theaetetus: What was that?
Stranger: Any power of doing or suffering in a degree however slight was held by us to be a sufficient definition of being?
Theaetetus: True.
Stranger: They deny this, and say that the power of doing or suffering is confined to becoming, and that neither power is applicable to being.
Theaetetus: And is there not some truth in what they say?
Stranger: Yes; but our reply will be, that we want to ascertain from them more distinctly, whether they further admit that the soul knows, and that being or essence is known.
Theaetetus: There can be no doubt that they say so.
Stranger: And is knowing and being known doing or suffering, or both, or is the one doing and the other suffering, or has neither any share in either?
Theaetetus: Clearly, neither has any share in either; for if they say anything else, they will contradict themselves.
Stranger: I understand; but they will allow that if to know is active, then, of course, to be known is passive. And on this view being, in so far as it is known, is acted upon by knowledge, and is therefore in motion; for that which is in a state of rest cannot be acted upon, as we affirm.
Theaetetus: True.
Stranger: And, O heavens, can we ever be made to believe that motion and life and soul and mind are not present with perfect being? Can we imagine that being is devoid of life and mind, and exists in awful unmeaningness an everlasting fixture?
Theaetetus: That would be a dreadful thing to admit, Stranger.
Stranger: But shall we say that has mind and not life?