n. In general, adherence to the supremacy of reason in matters of belief or conduct, in contradistinction to the submission of reason to authority; thinking for one's self.n. In theology:n. In general, the subjection of religious doctrine and Scriptural interpretation to the test of human reason or understanding; the rejection of dogmatic authority as against reason or conscience; rational latitude of religious thought or belief.n. More specifically, as used with reference to the modern sehool or party of rationalists, that system of doctrine which, in its extreme form, denies the existence of any authoritative and supernatural revelation, and maintains that the human reason is of itself, and unaided by special divine inspiration, adequate to ascertain all attainable religious truth.n. In metaphysics, the doctrine of a priori cognitions; the doctrine that knowledge is not all produced by the action of outward things upon the senses, but partly arises from the natural adaptation of the mind to think things that are true.