Moral relativism

In philosophy, moral relativism is the position that moral or ethical propositions do not reflect absolute and universal moral truths but instead are relative to social, cultural, historical or personal references, and that there is no single standard by which to assess an ethical proposition's truth. Relativistic positions often see moral values as applicable only within certain cultural boundaries or the context of individual preferences. An extreme relativist position might suggest that it is meaningless for the moral or ethical judgments or acts of one person or group to be judged by another, though most relativists propound a more limited version of the theory.

Some moral relativists—for example, the existentialist Jean-Paul Sartre—hold that a personal and subjective moral core lies or ought to lie at the foundation of individuals' moral acts. In this view, public morality is a reflection of social convention, and only personal, subjective morality is truly authentic.

http://en.wikipedia.org/wiki/Moral_relativism