David T. Runia

This volume of Proclus' commentary on Plato's Timaeus records Proclus' exegesis of Timaeus 27a–31b, in which Plato first discusses preliminary matters that precede his account of the creation of the universe, and then moves to the account of the creation of the universe as a totality. For Proclus this text is a grand opportunity to reflect on the nature of causation as it relates to the physical reality of our cosmos. The commentary deals with many subjects that have been of central interest to philosophers from Plato's time onwards, such as the question whether the cosmos was created in time, and the nature of evil as it relates to physical reality and its ontological imperfection.

Between about 2,600 and 2,400 years ago, a group of men lived whose thought formed the beginning of the discipline of philosophy. All contemporary material records of these men have disappeared, with the possible exception of a piece of a statue and some likenesses on early coins and vases. The very notion that these philosophers can be best understood as Presocratics is redolent with interpretative interventions. Although this view is not without ancient precedents, the driving force behind its dominance in the twentieth century was the great achievement of the German classical scholar Hermann Diels, which exercises authority to this day. The aim of this article is to examine the sources for Presocratic philosophy. It commences with the dominant legacy of Diels. Thereafter, it examines various strands of transmission streamlined by Diels. Finally, it reaches some tentative conclusions on what should be the way forward in future research.