You know that I held Epicurus strong And his opinion. Now I change my mind, And partly credit things that do presage. (5.1.78-80)

In these lines, Cassius speaks about believing in omens. He explains to Messala that while he never believed in omens or fate before, he has seen many signs along his way to tell him that they are possible. He continues to describe the signs he has seen, such as ravens and crows flying overhead as if “we were sickly prey” and “shadows” that seem “most fatal, under which our army lies.” While Cassius believes that he has a predetermined fate, he also wants to believe in his free will in going into battle with courage.

Even by the rule of that philosophy By which I did blame Cato for the death Which he did give himself … arming myself with patience To stay the providence of some high powers That govern us below. (5.1.102-109)

Brutus is responding to Cassius’s question of what he will do if they lose the battle against Antony and Octavius’s army. He says that he will trust in what the gods decide, which is an example of Brutus trusting in fate or what is meant to be. He also says that he would not prematurely kill himself simply to avoid the suffering of any fate. In this final act, this quote reveals how Brutus approaches the unknown by letting fate decide.

This day I breathed first. Time is come round, And where I did begin, there shall I end. My life is run his compass. (5.3.23-26)

As Cassius and his men are surrounded by Antony’s men, he sends Titinius to see if the troops are friends or enemies while also sending Pindarus to watch from a hilltop. In speaking these words, Cassius seems to be accepting his fate that his life has come full circle and that he will die on the day he was born. This declaration makes it clear that Cassius believes that his fate is to die and therefore, he will die. By letting go of his free will, Cassius reduces the chance that he survives this battle.