 The Life of Pythagoras by Plotinus’ pupil and editor, Porphyry (234-ca. 305) is one of our most important sources for Pythagoreanism (For what follows see Macris 2014). It was originally part of his now lost Philosophical History. Continuing interest in Pythagoras in later centuries led the Life of Pythagoras to be preserved separately and it is the only large section of the Philosophical History to survive. The Philosophical History  ended with Plato and clearly regarded Platonic philosophy as the true philosophy so that Pythagoras seems to have been highlighted as a key figure in the development of Plato’s philosophy. Porphyry’s Life of Pythagoras is particularly valuable, because he often clearly identifies his sources. This same penchant for identifying and seeking out important Pythagorean sources can be seen in his commentary on Ptolemy’s Harmonics (2nd CE), in which he preserves several genuine fragments of the early Pythagorean Archytas, along with some pseudo-Pythagorean material. In the Life of Pythagoras Porphyry does not structure his information according to any overarching theme but instead sets out the information derived from other sources in a simple and orderly way with the minimum of editorial intervention. Although he cites some fifteen sources, some going back to the fourth century BCE, it is likely that he did not use most of these sources but rather found them quoted in the four main sources, which he used directly: 1) Nicomachus’ Life of Pythagoras, 2) Moderatus’ Lectures on Pythagoreanism, 3) Antonius Diogenes’ novel Unbelievable Things Beyond Thule, and 4) a handbook of some sort. Since these sources come from the first and second centuries CE, Porphyry basically provides us with the picture of Pythagoras common in Middle Platonism. This Pythagoras is the prototype of the sage of old who was active as a teacher and tied to religious mystery. However, he is not yet Iamblichus’ priviliged soul sent to save humanity (Macris, 2014, 390). Porphyry provides little criticism of his sources and, although his life has a neutral factual tone, in contrast to Diogenes Laertius in his Life of Pythagoras, he includes no negative reports about Pythagoras.