a priori Meaning, Definition & Usage

adjective involving deductive reasoning from a general principle to a necessary effect; not supported by fact
- an a priori judgment
adjective satellite based on hypothesis or theory rather than experiment
adverb derived by logic, without observed facts

L. a (ab) + prior former.

(Logic) Characterizing that kind of reasoning which deduces consequences from definitions formed, or principles assumed, or which infers effects from causes previously known; deductive or deductively. The reverse of a posteriori.
(Philos.) Applied to knowledge and conceptions assumed, or presupposed, as prior to experience, in order to make experience rational or possible.
A priori, that is, form these necessities of the mind or forms of thinking, which, though first revealed to us by experience, must yet have preëxisted in order to make experience possible. Coleridge.