Appian of Alexandria Civil Wars 4.14.110

1. ὡς αὐτὸς ἐν τοῖς ὑπομνήμασιν ἔγραψεν. Plutarch used the same words with a single variation, substituting ἱστορεῖ ( relates) for ἔγραψεν ( has written). This identity of language would indicate that they drew from the same source, yet their accounts of the beginning of the battle differ from each other. Plutarch says that at a council of war held by Brutus and Cassius it was resolved to give battle on the following day, although Cassius favored delay; that after the resolution was taken Cassius was in good spirits, and expressed his confidence in victory; and that on the following morning the scarlet robe, which was the Roman signal of battle, was hung out in the camps of both Brutus and Cassius. Still, the two accounts are not necessarily conflicting, since one tells what took place in the republican camp, and the other what occurred in that of the triumvirs. Plutarch’s authority is Messala Corvinus, who commanded a legion under Brutus, and who was probably present at the council of war, since he relates a conversation that he had with Cassius immediately after it. ( Life of Brutus, 39, 40.)