Abstract
Moral virtue depends on self-control to override immoral impulses, so self-control failure can impair moral action. We discuss three components of self-control and how failure of any component can affect moral behavior. Lack of clear standards and lack of commitment to standards deprives the individual of clear inner guidance. Failure to monitor one's actions, as when self-awareness is low such as due to emotion or alcohol, deprives the individual of the ability to know whether behavior conforms to moral standards. Ego depletion signifies inadequate willpower to make oneself do what is right. Evidence supports these hypotheses but more is needed.