Axiology, also known as theory of the good and value theory (in a narrow sense of that term), is a branch of normative ethics concerned with what kind of things and outcomes are morally good, or intrinsically valuable. This is in contrast to the theory of the
right , which is concerned with what people morally ought to do.
There are many possible theories of value. Some hold that there is just one source of value, while others rely on multiple sources. Almost all theories agree that
well-being (also known as “welfare”) has value, and some theories, known as welfarist theories, hold that that it is the only thing which has intrinsic value. Non-welfarist theories recognize other sources of value, such as fairness, equality, or beauty.