I give the words partly from Diogenes, partly from Sextus, as I think they would be most likely to stand.
[583] Xenophanês ap. Sext. Emp. adv. Mathem. vii, 49.
[584] The satyrical writer Timon (ap. Sext. Emp. ix, 57), speaking in very respectful terms about Protagoras, notices particularly the guarded language which he used in this sentence about the gods; though this precaution did not enable him to avoid the necessity of flight. Protagoras spoke:—
Πᾶσαν ἔχων φυλακὴν ἐπιεικείης· τὰ μὲν οὐ οἱ
Χραίσμησ᾽, ἀλλὰ φυγῆς ἐπεμαίετο ὄφρα μὴ οὕτως
Σωκρατικὸν πίνων ψυχρὸν πότον Ἀΐδα δύῃ.
It would seem, by the last line as if Protagoras had survived Sokratês.
[585] Plato, Theætet. 18, p. 164, E. Οὔτι ἄν, οἶμαι, ὦ φίλε, εἴπερ γε ὁ πατὴρ τοῦ ἑτέρου μύθου ἔζη—ἀλλὰ πολλὰ ἂν ἤμυνε· νῦν δὲ ὄρφανον αὐτὸν ὄντα ἡμεῖς προπηλακίζομεν ... ἀλλὰ δὴ αὐτοὶ κινδυνεύσομεν τοῦ δικαίου ἕνεκ᾽ αὐτῷ βοηθεῖν.
This theory of Protagoras is discussed in the dialogue called Theætetus, p. 152, seq., in a long but desultory way.
See Sextus Empiric. Pyrrhonic. Hypol. i. 216-219, et contra Mathematicos, vii, 60-64. The explanation which Sextus gives of the Protagorean doctrine, in the former passage, cannot be derived from the treatise of Protagoras himself; since he makes use of the word ὕλη in the philosophical sense, which was not adopted until the days of Plato and Aristotle.