Temperance (Sophrosyne in Greek is defined as moderation in action, thought, or feeling; restraint) has been studied by religious thinkers, philosophers, and more recently, psychologists, particularly in the positive psychology movement. It is considered a virtue, a core value that can be seen consistently across time and cultures (see Historical and Religious Perspectives). It is considered one of the four Cardinal Virtues, for it is believed that no virtue could be sustained in the face of inability to control oneself, if the virtue was opposed to some desire. It is also one of the six main categories of the VIA Character Strengths (see Major Theoretical Approaches). Temperance is generally defined by control over excess, so that it has many such classes , such as abstinence, chastity, modesty, humility, prudence, self-regulation, and forgiveness and mercy; each of these involves restraining some impulse, such as sexual desire, vanity, or hatred.