Mistrust of good success hath done this deed. O hateful error, melancholy’s child, Why dost thou show to the apt thoughts of men The things that are not? O error, soon conceived, Thou never comest unto a happy birth, But kill’st the mother that engender’d thee!
Doubt about good success caused this. Oh, hateful mistake, child of sadness, Why do you show to the hopeful minds of men Things that aren’t real? Oh, mistake, quickly born, You never bring about a happy result, But you kill the mother who gave birth to you!
Messala · Act 5, Scene 3
Messala stands over the bodies of Cassius and Titinius after both have killed themselves, and he laments how doubt and false appearances destroyed them. The lines resonate because they name the play's deepest tragedy — not that men died, but that error killed the mother that conceived it, that mistrust of victory became a self-fulfilling prophecy. Messala's meditation reveals how the mind, not fate, can be the cruelest executioner.