  Even if he did not invent the word, what can we say about the philosophy of Pythagoras? For the reasons given in 1. The Pythagorean Question and 2. Sources above, any responsible account of Pythagoras’ philosophy must be based in the first place on the evidence prior to Aristotle and in the second place on evidence that our sources explicitly identify as deriving from Aristotle’s books on the Pythagoreans as well as from the books of his pupils such as Aristoxenus and Dicaearchus. There is general agreement as to what the pre-Aristotelian evidence is, although there are differences in interpretation of it. There is less agreement as to what should be included in Aristotle’s, Dicaearchus’ and Aristoxenus’ evidence. What one includes as evidence from these authors will have a significant effect on one’s picture of Pythagoras. One particularly pressing question is whether both chapters 18 and 19 of Porphyry’s Life of Pythagoras should be regarded as deriving from Dicaearchus, as the most recent editor proposes (Mirhady Fr. 40), or whether only chapter 18 should be included, as in the earlier edition of Wehrli (Fr.33). It is crucial to decide this question before developing a picture of the philosophy of Pythagoras since chapter 19, if it is by Dicaearchus, is our earliest summary of Pythagorean philosophy. Porphyry is very reliable about quoting his sources. He explicitly cites Dicaearchus at the beginning of Chapter 18 and names Nicomachus as his source at the beginning of chapter 20. The material in chapter 19 follows seamlessly on chapter 18: the description of the speeches that Pythagoras gave upon his arrival in Croton in chapter 18 is followed in chapter 19 by an account of the disciples that he gained as the result of those speeches and a discussion of what he taught these disciples. Thus, the onus is on anyone who would claim that Porphyry changes sources before the explicit change at the beginning of chapter 20. Chapter 19 provides a very restrained account of what can be reliably known about Pythagoras’ teachings and that very restraint is one of the strongest supporting arguments for its being based on Dicaearchus, since Porphyry or anyone else in the luxuriant later tradition would be expected to give a much more expanisve presentation of Pythagoras in accordance with the Neopythagorean view of him (Burkert 1972a, 122–123). Wehrli gives no reason for not including chapter 19 and the great majority of scholars accept it as being based on Dicaearchus (see the references in Burkert 1972a, 122, n.7). Zhmud (2012a, 157) following Philip (1966, 139) argues that the passage cannot derive from Dicaearchus, since it presents immortality of the soul with approval, whereas Dicaearchus did not accept its immortality. However, the passage merely reports that Pythagoras introduced the notion of the immortality of the soul without expressing approval or disapproval. Zhmud lists other features of the chapter that he regards as unparalleled in fourth-century sources (2012a, 157) but, since the evidence is so fragmentary, such arguments from silence can carry little weight. Nothing in the chapter is demonstrably late or inconsistent with Dicaearchus’ authorship so we must follow what is suggested by the context in Porphyry and regard it as derived from Dicaearchus.