Comparison of Dion and Brutus
Plutarch
Plutarch. Plutarch's Lives, Vol. VI. Perrin, Bernadotte, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd., 1918.
whereas, had not Dion himself been mistreated, he would not have gone to war. And this is made manifest by the letters of Plato, from which it is clear that Dion did not revolt, but was cast out from the tyranny, and therefore overthrew Dionysius.
Still further, it was the public good that made Brutus a friend even to Pompey, who was his foe, and an enemy to Caesar, since he determined both hatred and friendship by justice alone;
Dion, on the other hand, gave Dionysius much support in order to win his favour, when he was secure in his confidence, and when he was discredited by him, it was to gratify anger that he went to war.