Categorical imperative
Etymology
Coined by Immanuel Kant in his "Groundwork of the Metaphysics of Morals" (1785) as the German "kategorischer Imperativ." "Categorical" descends from Greek "katēgorikos" (asserting without condition) and "imperative" from Latin "imperare" (to command) — together naming a command that holds absolutely, not merely as a means to some further end.
noun phrase · /kat-uh-GOR-ih-kul im-PER-uh-tiv/
Kant’s supreme moral rule that you should act only on principles you could will to become universal laws binding on everyone.
What it names
A handle for the idea that morality is about consistent, universalizable rules rather than outcomes — reach for it to test whether an action would collapse if everyone did it.
Example
Before lying to get out of the meeting, she ran it through the categorical imperative and realized a world where everyone lied on demand would make promises meaningless.
Related idea
Contrast with consequentialism, which judges an act by its results; the categorical imperative judges the maxim behind the act, regardless of how things turn out.