value-relativism in that pluralism accepts limits to differences, such as when vital human needs are violated. Political scientists have often referred to societies as being pluralistic on the basis of the existence of several competing value systems. Littunen says that such societies exhibit value pluralism.

If values can be compared with virtues or duties then reference might also be made to the arguments of classical philosophy. Kant, for example, referred to "a conflict of duties" and the subject can be traced back to Plato's Statesman