STRANGER: And do they not say that one soul is just, and another unjust, and that one soul is wise, and another foolish? THEAETETUS: Certainly. STRANGER: And that the just and wise soul becomes just and wise by the possession of justice and wisdom, and the opposite under opposite circumstances? THEAETETUS: Yes, they do. STRANGER: But surely that which may be present or may be absent will be admitted by them to exist? THEAETETUS: Certainly. STRANGER: And, allowing that justice, wisdom, the other virtues, and their opposites exist, as well as a soul in which they inhere, do they affirm any of them to be visible and tangible, or are they all invisible? THEAETETUS: They would say that hardly any of them are visible. STRANGER: And would they say that they are corporeal? THEAETETUS: They would distinguish: the soul would be said by them to have a body; but as to the other qualities of justice, wisdom, and the like, about which you asked, they would not venture either to deny their existence, or to maintain that they were all corporeal. STRANGER: Verily, Theaetetus, I perceive a great improvement in them; the real aborigines, children of the dragon's teeth, would have been deterred by no shame at all, but would have obstinately asserted that nothing is which they are not able to squeeze in their hands. THEAETETUS: That is pretty much their notion. STRANGER: Let us push the question; for if they will admit that any, even the smallest particle of being, is incorporeal, it is enough; they must then say what that nature is which is common to both the corporeal and incorporeal, and which they have in their mind's eye when they say of both of them that they 'are.' Perhaps they may be in a difficulty; and if this is the case, there is a possibility that they may accept a notion of ours respecting the nature of being, having nothing of their own to offer. THEAETETUS: What is the notion? Tell me, and we shall soon see. STRANGER: My notion would be, that anything which possesses any sort of power to affect another, or to be affected by another, if only for a single moment, however trifling the cause and however slight the effect, has real existence; and I hold that the definition of being is simply power. THEAETETUS: They accept your suggestion, having nothing better of their own to offer. STRANGER: Very good; perhaps we, as well as they, may one day change our minds; but, for the present, this may be regarded as the understanding which is established with them. THEAETETUS: Agreed. 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.