In the Sophist the Eleatic Stranger, questioning the young Theaetetus, offers two sentences, “Theaetetus sits” and “Theaetetus … is flying”, to show that every sentence has a “quality”. The Stranger is working to explain how false speech is possible, a problem the dialogue takes up against the sophists. It sits under “Correspondence” as the early account of a sentence that “says what is true” and one that “says what is other than true”.
Read in contextSTRANGER. I will repeat a sentence to you in which a thing and an action are combined, by the help of a noun and a verb; and you shall tell me of whom the sentence speaks.
THEAETETUS. I will, to the best of my power.
STRANGER. ‘Theaetetus sits’—not a very long sentence.
THEAETETUS. Not very.
STRANGER. Of whom does the sentence speak, and who is the subject? that is what you have to tell.
THEAETETUS. Of me; I am the subject.
STRANGER. Or this sentence, again—
THEAETETUS. What sentence?
STRANGER. ‘Theaetetus, with whom I am now speaking, is flying.’
THEAETETUS. That also is a sentence which will be admitted by every one to speak of me, and to apply to me.
STRANGER. We agreed that every sentence must necessarily have a certain quality.
THEAETETUS. Yes.
STRANGER. And what is the quality of each of these two sentences?
THEAETETUS. The one, as I imagine, is false, and the other true.
STRANGER. The true says what is true about you?
THEAETETUS. Yes.
STRANGER. And the false says what is other than true?
THEAETETUS. Yes.
STRANGER. And therefore speaks of things which are not as if they were?
THEAETETUS. True.
STRANGER. And say that things are real of you which are not; for, as we were saying, in regard to each thing or person, there is much that is and much that is not.
THEAETETUS. Quite true.