True speech (ἀληθὴς λόγος): in the Sophist (263b) the Eleatic Stranger builds the simplest λόγος out of a noun (ὄνομα) and a verb (ῥῆμα) — «Theaetetus sits» — and calls it true when it «says of what is that it is, as it is» (λέγει τὰ ὄντα ὡς ἔστιν). For Plato it is connected speech, not the isolated name, that bears truth: a name by itself asserts nothing.
True speech is the direct opposite of false speech (ψευδὴς λόγος): both are introduced by one and the same move and on one example (Soph. 263b). Carried through «in the soul» to a silent affirmation, it yields true opinion (ἀληθὴς δόξα) (Soph. 264a); cf. Philebus 37b, where both opinion and the pleasure bound up with it may be true or false.