Generally speaking, morality is a set of rules guiding the behavior of an individual in his personal and social life. The question, for the psychologist, is to know how these rules install themselves in consciousness. If they came only from the social environment, by learning or conformity, morality would change as one crosses a river, as Pascal mentions ironically.

Those, in turn, who are looking for more universal moral principles consider morality as a system of elementary rules and duties. Unlike legal norms, moral norms only put a general frame to action: every case is specific, and individuals are not simply interchangeable. Further, as Bunge observes, legal systems put more stress on rights than on duties (there is a declaration of human rights but no declaration of human obligations), whereas morality puts stress on obligations. Aristotle already noted that morality rules elementary behavior and is spoken in words like "you must, should, need...", whereas law rules what each one gets.