Why do you think Cassius does not tell Brutus about his fears?
Cassius sees omens that the defeat of their army is at hand: “two mighty eagles fell, and there they perched, / Gorging and feeding from our soldiers’ hands” (5.1.88-89). In addition, it is his birthday, making the day additionally significant. However, he refuses to accept these omens as a true sign, instead resolving “to meet all perils very constantly” (100). He does not tell Brutus his fears because he does not want to accept them himself. In addition, he does not want to worry his friend. As a result, when Brutus returns to talk to him, he says nothing about these omens, instead commenting jut th opposite: “The gods today stand friendly that we may, / Lovers in peace, lead on our days to age” (101-104). Their parting in Act 5 Scene 1 proves very moving, Cassius encouraging his friend with the hope for the best, and resolving they will not return to Rome as prisoners. “If we do meet again, we’ll smile indeed; / If not, ‘tis true this parting was well made” (131-32). Whatever else we might say about Cassius at the beginning of the play, but the end he shows a warm friendship for Brutus as Brutus expresses the same for him.