In metaethics, the view that moral judgments are prescriptions and therefore have the logical form of imperatives. Prescriptivism was first advocated by Richard M. Hare
born 1919
in The Language of Morals (1952).
Hare argued that it is impossible to derive any prescription from a set of descriptive sentences, but tried nevertheless to provide a foothold for moral reasoning in the constraint that moral judgments must be "universalizable": that is, that if one judges a particular action to be wrong, one must also judge any relevantly similar action to be wrong. Universalizability is not a substantive moral principle but a logical feature of the moral terms: anyone who uses such terms as "right" and "ought" is logically committed to universalizability.