The Histories · 2.49

Now I think that Melampus the son of Amytheon was not without knowledge of these rites of sacrifice, but was acquainted with them: for Melampus is he who first set forth to the Hellenes the name of Dionysos and the manner of sacrifice and the procession of the phallos. Strictly speaking indeed, he when he made it known did not take in the whole, but those wise men who came after him made it known more at large. Melampus then is he who taught of the phallos which is carried in procession for Dionysos, and from him the Hellenes learnt to do that which they do. I say then that Melampus being a man of ability contrived for himself an art of divination, and having learnt from Egypt he taught the Hellenes many things, and among them those that concern Dionysos, making changes in some few points of them: for I shall not say that that which is done in worship of the god in Egypt came…

Herodotus of Halicarnassus · trans. G. C. Macaulay, 1890
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