Fact–value distinction

The fact–value distinction is a fundamental epistemological distinction between:

1. Statements of fact (positive or descriptive statements), which are based upon reason and observation, and which are examined via the empirical method.
2. Statements of value (normative or prescriptive statements), such as good and bad, beauty and ugliness, which encompass ethics and aesthetics, and which are studied via axiology.

This barrier between fact and value, as construed in epistemology, implies it is impossible to derive ethical claims from factual arguments or to defend the former using the latter.

The fact–value distinction is closely related to, and derived from, the is–ought problem in moral philosophy, characterized by David Hume. The terms are often used interchangeably, though philosophical discourse concerning the is–ought problem does not usually encompass aesthetics.