Aetius

Who is Aetius?

Aetius was a 2nd-century BCE doxographer and Eclectic philosopher.

None of Aetius' works survive today, but he solves a mystery about two major compilations of philosophical quotes. There are two extant books named Placita Philosophorum and Eclogae Physicae. The first of these is Pseudo-Plutarch and the second is by Stobaeus. They are clearly both abridgements of a larger work. Hermann Diels, in his great Doxographi Graeci, discovered that the 5th-century theologician Theodoret had full versions of the quotes which were shortened in the abridgements. This means that Theodoret had managed to procure the original book which Pseudo-Plutarch and Stobeaus had shortened. He calls this book "Aetiou tên peri areskontôn sunagôgên," and therefore we ascribe the original Placita to Aetius.

Diels claimed that Aetius himself was merely abridging a work which Diels called the Vetusta Placita. Unlike Aetius, whose existence is attested by Theodoret, the Vetusta Placita is Diels' invention and is generally disregarded by modern classicists, e.g., the 1999 Cambridge History of Hellenistic Philosophy.