The history of Pythagoreanism is littered with different and incompatible interpretations, to the point that Kahn (1974) suggested that, instead of another thesis on Pythagoreanism, it would be preferable to assess traditions with the aim of producing a good historiographical presentation. This almost fourty-year-old observation by Kahn, directs the author of this book towards a fundamentally historiographical rather than philological brand of work, that is, one neither exclusively devoted to the exegesis of sources such as Philolaus, Archytas or even of one of the Hellenistic Lives nor even to the theoretical approach of one of the themes that received specific contributions from Pythagoreanism, such as mathematics,