Demetrius of Phaleron

The treatise On Style (De Elocutione) attributed to Demetrius is one of the most important works of ancient literary criticism. Its authorship is disputed — the traditional attribution to Demetrius of Phalerum (c. 350–280 BC), the Peripatetic philosopher who governed Athens for Cassander, is almost certainly wrong. The work probably dates to the first century BC or first century AD, but its author remains unknown.

The treatise identifies four styles of prose: the grand, the elegant, the plain, and the forceful. Each is analysed in terms of diction, composition, and subject matter, with copious examples from Greek literature. The treatment is practical rather than theoretical — the author is interested in how effects are achieved, not in philosophical foundations. His advice on letter-writing is the earliest surviving discussion of the epistolary form.

The work stands alongside Aristotle's Rhetoric, Longinus' On the Sublime, and the rhetorical writings of Dionysius of Halicarnassus as one of the fundamental texts of ancient literary theory. Its influence on Renaissance rhetoric was considerable.