1st century BC) was an Ancient Greek rhetorician of the Rhodian school and teacher of rhetoric in Rome,[1] where the Suda states he died at an advanced age.
Hermagoras's chief opponents were Posidonius of Rhodes, who is said to have contended with him in argument in the presence of Pompey, and Athenaeus.
[1][5] 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.
[9][10] 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.
[1] Hermagoras' method of dividing a topic into its "seven circumstances" (who, what, when, where, why, in what way, by what means), which he may have borrowed from Aristotle, 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.