Xenophilus (Greek: Ξενόφιλος; 4th century BC), of Chalcidice,[2] was a Pythagorean philosopher and musician who lived in the first half of the 4th century BC.[3] Aulus Gellius relates that Xenophilus was the intimate friend and teacher of Aristoxenus and implies that Xenophilus taught him Pythagorean doctrine.[4] He was said to have belonged to the last generation of Pythagoreans, and he is the only Pythagorean known to have lived in Athens in the 4th century BC.[5]
According to Diogenes Laërtius, Aristoxenus wrote that when Xenophilus was once asked by someone how he could best educate his son, Xenophilus replied, "By making him the citizen of a well-governed state."[6] In the Macrobii of Pseudo-Lucian, Aristoxenus is supposed to have said that Xenophilus lived 105 years.[7] Xenophilus enjoyed considerable fame in the Renaissance, apparently because of Pliny's claim that he lived 105 years without ever being sick.[8]