Diogenes Laertius Vitae philosophorum 2.5.23

[23] For in the general flight of the Athenians he personally retired at his ease, quietly turning round from time to time and ready to defend himself in case he were attacked. Again, he served at Potidaea, whither he had gone by sea, as land communications were interrupted by the war ¹ ; and while there he is said to have remained a whole night without changing his position, and to have won the prize of valour. But he resigned it to Alcibiades, for whom he cherished the tenderest affection, according to Aristippus in the fourth book of his treatise On the Luxury of the Ancients. Ion of Chios relates that in his youth he visited Samos in the company of Archelaus; and Aristotle that he went to Delphi; he went also to the Isthmus, according to Favorinus in the first book of his Memorabilia.