Athenian orator, statesman, and philosopher who was appointed governor of Athens by the Macedonian general Cassander (317 BC). He favoured the upper classes and gave effect to the ideas of such earlier political theorists as Aristotle. When the old democracy was restored in 307, Demetrius escaped to Thebes and later to Egypt, where he became prominent at the court of Ptolemy I, enjoying a high reputation as an orator.