Dion and Brutus studied philosophy and then killed a ruler. Dion drove Dionysius from Syracuse. Brutus joined the men who killed Caesar. Both were betrayed afterward, Dion by Callippus and Brutus by the loss at Philippi.

Plutarch gives Dion the clearer case: Dionysius was an avowed tyrant, and Dion did not strike a man who had spared his life. The gravest charge against Brutus is that Caesar had saved him and honoured him, and Brutus killed him anyway. The two causes, he says, were not the same.