A priori

A` pri`o´ri

	1.	(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.
	3.	(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.

Adj.	1.	a priori - involving deductive reasoning from a general principle to a necessary effect; not supported by fact; "an a priori judgment" Antonyms: a posteriori - involving reasoning from facts or particulars to general principals or from effects to causes; "a posteriori demonstration"
	2.	a priori - based on hypothesis or theory rather than experiment
Adv.	1.	a priori - derived by logic, without observed facts Antonyms: a posteriori - derived from observed facts