The Pros and Cons of Plato's Against Proclus

Aristotle's commitment to an eternal universe was so emphatic that no ancient philosophers seriously questioned it. Convenient doubts about Aristotle's confidence would be raised only later by medieval thinkers like Maimonides and Thomas Aquinas. Some middle Platonists, notably Plutarch and Atticus, read Plato's dialogue Tymius as endorsing a beginning in time for the universe. But from Plotinus onwards, Platonists took this to be a misreading of Plato.