- reliance on reason rather than intuition to justify one's beliefs or actions
- the doctrine that knowledge about reality can be obtained by reason alone without recourse to experience
- the belief that knowledge and truth are ascertained by rational thought and not by divine or supernatural revelation
WordReference Random House Learner's Dictionary of American English © 2026
ra•tion•al•ism /ˈræʃənəlˌɪzəm/USA pronunciation
n. [uncountable]
WordReference Random House Unabridged Dictionary of American English © 2026- the principle or doctrine of using human reason as the basis for matters of opinion, belief, or conduct.
- a doctrine in philosophy that stresses the use of reason as opposed to religious faith.
ra•tion•al•ism
(rash′ə nl iz′əm),USA pronunciation n.
ra′tion•al•ist, n.
ra′tion•al•is′tic, ra′tion•al•is′ti•cal, adj.
ra′tion•al•is′ti•cal•ly, adv.
- the principle or habit of accepting reason as the supreme authority in matters of opinion, belief, or conduct.
- Philosophy
- the doctrine that reason alone is a source of knowledge and is independent of experience.
- (in the philosophies of Descartes, Spinoza, etc.) the doctrine that all knowledge is expressible in self-evident propositions or their consequences.
- Religion[Theol.]the doctrine that human reason, unaided by divine revelation, is an adequate or the sole guide to all attainable religious truth.
- Architecture(often cap.)
- a design movement principally of the mid-19th century that emphasized the development of modern ornament integrated with structure and the decorative use of materials and textures rather than as added adornment.
- the doctrines and practices of this movement. Cf. functionalism (def. 1).
- rational + -ism 1790–1800
ra′tion•al•is′tic, ra′tion•al•is′ti•cal, adj.
ra′tion•al•is′ti•cal•ly, adv.
Collins Concise English Dictionary © HarperCollins Publishers::
rationalism /ˈræʃənəˌlɪzəm/ n
'rationalism' also found in these entries (note: many are not synonyms or translations):