<p><strong>Noun</strong></p><ul><li>the principle or habit of accepting reason as the supreme authority in matters of opinion, belief, or conduct.</li><li>Philosophy: the doctrine that reason alone is a source of knowledge and is independent of experience.</li><li>(in the philosophies of Descartes, Spinoza, etc.) the doctrine that all knowledge is expressible in self-evident propositions or their consequences.</li><li>Theology: the doctrine that human reason, unaided by divine revelation, is an adequate or the sole guide to all attainable religious truth.</li><li>Architecture: (often initial capital letter) 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.</li><li>the doctrines and practices of this movement.</li></ul>