He once gave Hipponicus a blow with his fist — Hipponicus, the father of Callias, a man of great reputation and influence owing to his wealth and family — not that he had any quarrel with him, or was a prey to anger, but simply for the joke of the thing, on a wager with some companions.
Edition :
Plutarch Lives IV: Alcibiades and Coriolanus, Lysander and Sulla, Ed. Jeffrey Henderson, trans. Bernadotte Perrin (The Loeb Classical Library 80), Harvard University Press: Cambridge/MA - London 2000 (first ed. 1916).