Value pluralism

In philosophical ethics, value pluralism (also known as ethical pluralism or moral pluralism) is the idea that there are several values which may be equally correct and fundamental, and yet in conflict with each other. In addition, value-pluralism postulates that in many cases, such incompatible values may be incommensurable, in the sense that there is no objective ordering of them in terms of importance.

Value-pluralism is a theory in metaethics, rather than a theory of normative ethics, or a set of values in itself. Oxford philosopher and historian of ideas, Isaiah Berlin, is credited with being the first to write a substantial work describing the theory of value-pluralism, bringing it to the attention of academia. (cf. the Isaiah Berlin Virtual Library).

Context
Value-pluralism is an alternative to both moral relativism and moral absolutism (which Berlin called monism). An example of value-pluralism is the idea that the moral life of a nun is incompatible with that of a mother, yet there is no purely rational measure of which is preferable. Hence, moral decisions often require radical preferences with no rational calculus to determine which alternative is to be selected.

Value-pluralism differs from value-relativism in that pluralism accepts limits to differences, such as when vital human needs are violated.

Adherents
William James anticipated Berlinian value-pluralism in an essay on The Moral Philosopher and the Moral Life, which he first delivered as a lecture in 1891. He wrote that none "of the measures [of goodness] that have been actually proposed has, however, given general satisfaction (...) The various ideals have no common character apart from the fact that they are ideals. No single abstract principle can be so used as to yield to the philosopher anything like a scientifically accurate and genuinely useful casuistic scale."

Joseph Raz and many others have done further work clarifying and defending value-pluralism.

Critics
An important critique of value-pluralism has been advanced by the philosopher Charles Blattberg, who was a student of Berlin's. Another notable critic of value-pluralism in recent times is Ronald Dworkin, who attempts to forge a liberal theory of equality from a monist starting-point.