 We know nothing of Leon and Bathyllus, except that Iamblichus, in On the Pythagorean Way of Life (=VP), lists a Pythagorean named Leon from Metapontum and a Pythagorean Bathylaus from Poseidonia (Paestum), both Greek cities of southern Italy (VP 267). Bro(n)tinus is identified as a Pythagorean from Croton in some places (D.L. VIII. 42; Iamb. VP 132) and from Metapontum in others (VP 194, 267). He is either the father or the husband of Theano, who is in turn either the wife or student of Pythagoras. Does this “dedication” of his book to Pythagoreans indicate that Alcmaeon himself was a Pythagorean? Even if this is a dedication, it does not follow that Alcmaeon agreed with the views of his addressees. Comparison with Empedocles’ address to Pausanias suggests, moreover, that what we have is not a dedication but an exhortation or an attempt to instruct (Vlastos 1953, 344, n. 25). Comparison with other early Greek prose writers such as Hecataeus and Heraclitus shows that books could begin with criticism of the views of others so that Alcmaeon’s address to these Pythagoreans may be polemical (Kouloumentas 2018).