he can who believes he can

proverb If you have faith in your ability to do something, then you will be able to do it. Would you stop putting yourself down? He can who believes he can—make that your new mantra. A: "There's no way I'll win the student council election." B: "Not with that attitude. Come on—he can who believes he can!" Sean's a bright kid, but he's really pessimistic, and I do think it holds him back. "He can who believes he can," right?