Socr. How then can any one form false judgments? For it is impossible to form judgments in any other way than this, since we either know or do not know all things, and in these it appears to be by no means possible to form false judgments.
Theæ. Most true.
Socr. Ought we, then, to consider the object of our enquiry, not by proceeding according to knowing and not knowing, but according to being and not being?
Theæ. How do you mean?
Socr. Whether it is not universally true, that he who thinks things that are not, with respect to any thing whatever, must unavoidably form a false judgment, however intelligent he may be in other respects.
Theæ. That is reasonable, Socrates.
Socr. How then? what shall we say, Theætetus, if any one should ask us, “Is it possible for any one to do what you say, and can any man think that which is not, whether respecting any real object or abstract essence?” And we, it seems, shall say to this, “When he who thinks does not think what is true.” What else can we say?
Theæ. Nothing else.
112. Socr. Does a thing of this kind happen also in other cases?
Theæ. Of what kind?
Socr. If a person sees something, and yet sees nothing.
Theæ. But how can that be?
Socr. But if he sees some one thing, he sees something that exists; and do you think that one thing is ever among things that do not exist?
Theæ. I do not.
Socr. He, therefore, who sees some one thing sees that which exists.
Theæ. It appears so.
Socr. And, therefore, he who hears something, both hears some one thing, and hears that which exists.
Theæ. Yes.
Socr. And doubtless he who touches both touches some one thing, and that which exists, since it is one thing?
Theæ. And this too.
Socr. Does not he then who judges, judge some one thing?
Theæ. Of necessity.
Socr. And does not he who judges some one thing, judge something that exists?
Theæ. I grant it.
Socr. He therefore who judges what does not exist, judges nothing.
Theæ. It appears not.
Socr. But he who judges nothing, does not judge at all.
Theæ. That is evident, as it seems.
The Works of Plato (vol. 1 of 6) · The Wunder Library — complete classics, free to read, with narration.