These volumes form part of the large international Theophrastus Project started by Brill in 1992 and edited by W.W. Fortenbaugh and others. Together with volumes comprising the texts and translations, the commentary volumes provide a new generation of classicists with an up-to-date collection of the fragments and testimonia relating to Theophrastus (approximately 370-288/5 B.C.), Aristotle's pupil and successor as head of the Lyceum.