  It is difficult to establish a chronology of Proclus’ works. The Platonic Theology is generally considered to be his last work. In writing the Theology Proclus heavily depends on his interpretation of the Parmenides and often refers to his commentary on this dialogue, which must have been finished some time before. We know from Marinus (Life of Proclus §13) that Proclus finished his Commentary on the Timaeus by the age of 27. However, it cannot be excluded that Proclus rewrote or modified it later. As the Alcibiades came at the beginning of the curriculum in the school, its commentary may also be an early work. The Commentary on the Republic is not a proper commentary, but a collection of several essays on problems and sections in this dialogue. These essays may have been written at different times in Proclus’ life and only later put together (by Proclus himself or by someone else). The Hypotypôsis (Exposition of Astronomical Hypotheses) was written in the year after Proclus’ exile in Lydia, but we do not know when exactly that took place. The Tria opuscula all deal with similar topics, but they need not have been composed at the same time. There are plausible arguments to put the second treatise, On What Depends on Us, some years after the events forcing Proclus to go into exile. The first treatise, which in some parts depends very much on Plutarch (of Chaironea, 1st–2nd c. C.E.), could be set earlier in his career. It also contains a discussion on the nature of evil, which is much simpler than what we find in the treatise On the Existence of Evils, which is more sophisticated and probably was composed later. Because of its introductory character, one may be inclined to consider the Elements of Physics as an early work. This has also been claimed for the Elements of Theology, which, however, shows all the sophistication of Proclus’s mature thought. It may be possible that Proclus revised this text several times in his career.