A value is a universal value if it has the same value or worth for all, or almost all, people. Spheres of human value encompass morality, aesthetic preference, traits, human endeavour, and social order. Whether universal values exist is an unproven conjecture of moral philosophy and cultural anthropology, though it is clear that certain values are found across a great diversity of human cultures, such as primary attributes of physical attractiveness whereas other attributes are subject to aesthetic relativism as governed by cultural norms. This objection is not limited to aesthetics. Relativism concerning morals is known as moral relativism, a philosophical stance opposed to the existence of universal moral values.