Value is the worth of something, usually understood as covering both positive and negative degrees corresponding to the terms good and bad. Values influence many human endeavors related to emotion, decision-making, and action. Value theorists distinguish various types of values, like the contrast between intrinsic and instrumental value. An entity has intrinsic value if it is good in itself, independent of external factors. An entity has instrumental value if it is useful as a means leading to other good things. Other classifications focus on the type of benefit, including economic, moral, political, aesthetic, and religious values. Further categorizations distinguish absolute values from values that are relative to something else.
Diverse schools of thought debate the nature and origins of values. Value realists state that values exist as objective features of reality. Anti-realists reject this, with some seeing values as subjective human creations and others viewing value statements as meaningless. Regarding the sources of value, hedonists argue that only pleasure has intrinsic value, whereas desire theorists discuss desires as the ultimate source of value. Perfectionism, another approach, emphasizes the cultivation of characteristic human abilities. Value pluralism identifies diverse sources of intrinsic value, raising the issue of whether values belonging to different types are comparable. Value theorists employ various methods of inquiry, ranging from reliance on intuitions and thought experiments to the analysis of language, description of first-person experience, observation of behavior, and surveys.