Hermagoras of Temnos

Hermagoras (Ancient Greek: Ἑρμαγόρας, fl. 1st century BC), of Temnos, was an Ancient Greek rhetorician of the Rhodian school and teacher of rhetoric in Rome.

He appears to have tried to excel as an orator (or rather declaimer) as well as a teacher of rhetoric. But it is especially as a teacher of rhetoric that he is known to us. The members of his school, among whom numbered the jurist Titus Accius, called themselves Hermagorei. Hermagoras's chief opponent was Posidonius of Rhodes, who is said to have contended with him in argument in the presence of Pompey.

He devoted particular attention to what is called inventio, and made a peculiar division of the parts of an oration, which differed from that adopted by other rhetoricians.Cicero opposes his system, but Quintilian defends it, though in some parts the latter censures what Cicero approves of. But in his eagerness to systematize the parts of an oration, he was said to have entirely lost sight of the practical point of view from which oratory must be regarded.

He appears to have been the author of several works which are lost: the Suda mentions (graeca sunt, non leguntur) Ρητορικαί, Περί εξεργασίας, Περί φράσεως, Περί σχημάτων, and Περί πρέποντος, although perhaps some or all of these should be attributed to his younger namesake, Hermagoras Carion, the pupil of Theodorus of Gadara.

Hermagoras' method of dividing a topic into its "seven circumstances" (who, what, when, where, why, in what way, by what means) provided the roots of the "5 W's" used widely in journalism, education, and police investigation to ensure thoroughness in the coverage of a particular incident or subject matter.

...
Wikipedia