 The sentence in bold above is missing in one of the major manuscripts and Alexander makes no mention of it in his commentary on the Metaphysics. It does appear in the other two major manuscripts and in Asclepius’ commentary. A number of scholars have regarded it as a remark by a later commentator, which has crept into the text (e.g., Ross 1924, 152; Burkert 1972, 29, n.60) and this is the view of the most recent editor (Primavesi 2012, 447–8). It is a surprising remark for Aristotle to make, since he only refers to Pythagoras once elsewhere in all his extant writings and throughout this passage of the Metaphysics refers to the Pythagoreans or Italians in the plural. Other scholars regard the remark as genuine (e.g., Wachtler 1896; Guthrie 1962, 341–3; Zhmud 2012a, 122). Even if we accept the remark as genuine, the assertion that Alcmaeon “was” (egeneto) in the old age of Pythagoras is ambiguous. Does it mean that Alcmaeon was born in the old age of Pythagoras, or that he lived (flourished?) in the old age of Pythagoras? Diels emended the sentence to say that Alcmaeon was “young” in the old age of Pythagoras and this emendation is supported by a similar remark found in Iamblichus (VP 104). Although Diels accepted the text as Aristotelian, others have seen the parallel with Iamblichus as evidence that it is a remark by a later commentator and have pointed out that the report in Iamblichus involves several chronological impossibilities (e.g., that Philolaus was young in the old age of Pythagoras). Moreover, Diels’ text suggests that the purpose of the remark was to show Alcmaeon’s dependence on Pythagoras, which would show that the remark cannot be due to Aristotle, who has just distinguished Alcmaeon from the Pythagoreans and expressed doubts as to who influenced whom (Primavesi 2012, 447–8). Even if the remark is unlikely to go back to Aristotle, his doubts about who influenced whom suggest that Alcmaeon belonged to the late sixth or early fifth century (Schofield 2012, 156), which would argue against the late date of 440 adopted by Mansfeld (2013, 78, n. 1). One group of scholars thus dates the publication of Alcmaeon’s book to around 500 (Burkert 1972, 292; Kirk, Raven, Schofield 1983, 339 [early 5th]; Zhmud 2012a, 122 [not later than 490]) so that he would have been born around 540. Another group has him born around 510 so that his book would have been published in 470 or later (Guthrie 1962, 358 [480–440 BCE]; Lloyd 1991, 168 [490–430 BCE]). In either case Alcmaeon probably wrote before Empedocles, Anaxagoras, and Philolaus. He is either the contemporary or the predecessor of Parmenides. Attempts to date him on the basis of internal evidence alone, i.e. comparison of his doctrines with those of other thinkers, have led to the widest divergence of dates. Edelstein says that he may have lived in the late fifth century (1942, 372), while Lebedev makes him active in the late 6th (1993).