Axiology (from Greek ἀξία, axia: "value, worth"; and -λογία, -logia: "study of") is the philosophical study of value. It includes questions about the nature and classification of values and about what kinds of things have value. It is intimately connected with various other philosophical fields that crucially depend on the notion of value, like ethics, aesthetics or philosophy of religion. It is also closely related to value theory and meta-ethics. The term was first used by Eduard von Hartmann in 1887 and by Paul Lapie in 1902.
The distinction between intrinsic and extrinsic value is central to axiology. One conceptualization holds that something is intrinsically valuable if it is good in itself or good for its own sake. It is usually held that intrinsic value depends on certain features of the valuable entity. For example, an experience may be said to be intrinsically valuable by virtue of being (because it is) pleasurable or beautiful or "true" (e.g., the ascertainment of a fact c