“Men at some time are masters of their fates.”
Circumstances matter, but people also have moments when their own decisions meaningfully shape what follows.
Source details
Julius Caesar, Act I, Scene 2, in the 1919 Yale Shakespeare edition edited by Lawrence Mason. Cassius says ‘Men at some time are masters of their fates’ immediately before the fuller stars/underlings argument; the retained short record is part of the same local persuasion scene.