the Pythagoras legend, Pythagorean practice, and Pythagorean doctrine. (...) Whatever may have been Aristotle's attitude towards the legends and the so-called Pythagorean way of life, it is clear that he was extremely interested in certain doctrines which he called Pythagorean. These are discussed frequently and at length in several of the treatises (...). The main part of the present book is naturally concerned with these matters, above all with the Opposites, with Cosmology, and with Number Theory. On these issues Philip reaches a number of specific conclusions. He believes that in general when Aristotle refers to Pythagoreans he is in fact referring to Pythagoras himself and not to any later group or groups (...). Moreover we must not suppose that the use of the plural by Aristotle when referring to Pythagoreans implies any kind of religious society or brotherhood. (...) The attempt to reconstruct everything about the history of earlier Pythagoreanism from Aristotle's evidence alone will not do, because Aristotle is only concerned with certain details of Pythagorean doctrines and not with the whole range even in the sphere of doctrine. Just for this very reason, much of what we are offered by Philip about Pythagoras comes from post-Aristotelian as well as pre-Aristotelian sources, and at many points, inevitably, we are involved in a discussion of the whole tradition from Iamblichus backwards. (...) On the other hand the analysis of Aristotle's evidence is neither as clear nor as detailed as desirable.' (G.B. KERFERD in The Classical Review (New Series), 1969, pp.202-203).