HERMOGENES, of Tarsus, Greek rhetorician, surnamed Ξυστήρ (the polisher), flourished in the reign of Marcus Aurelius (A.D. 161–180). His precocious ability secured him a public appointment as teacher of his art while as yet he was only a boy; but at the age of twenty-five his faculties gave way, and he spent the remainder of his long life in a state of intellectual impotence. During his early years, however, he had composed a series of rhetorical treatises, which became popular text-books, and the subject of subsequent commentaries. Of his Τέχνη ῥητορική we still possess the sections Περὶ τῶν στάσεων (on legal issues), Περὶ εὑρέσεως (on the invention of arguments), Περὶ ἰδεῶν (on the various kinds of style), Περὶ μεθόδου δεινότητος (on the method of speaking effectively), and Προγυμνάσματα (rhetorical exercises).

Editions by C. Walz (1832), and by L. Spengel (1854), in their Rhetores Graeci; bibliographical note on the commentaries in W. Christ, Geschichte der griechischen Literatur (1898).