## Definition - The [[Epistemology|epistemological]] view that **reason is the primary source of knowledge**, independent of sensory experience - Holds that certain truths (e.g., mathematics, logic, metaphysical principles) are knowable through pure reasoning - Often contrasted with [[Empiricism]], which emphasizes knowledge through experience ## Core Concepts - **Innate ideas**: Certain concepts or truths are inherent in the mind (e.g., God, mathematical principles) - **A priori knowledge**: Knowledge independent of experience, discoverable through reason alone - **Deductive reasoning**: Deriving specific truths from general principles - **Necessary truths**: Beliefs that must be true and cannot be otherwise (e.g., 2+2=4) ## Key Characteristics - Seeks certainty through reason, often skeptical of the reliability of the senses - Provides foundations for metaphysics, mathematics, and ethics - Frames knowledge as structured, logical, and discoverable by the intellect - Balances or synthesizes with [[Empiricism]] in modern [[philosophy]] (e.g., Kant) ## Historical Perspectives - **René Descartes**: Advocated methodic doubt, "Cogito, ergo sum," and innate ideas - **Baruch Spinoza**: Applied geometric reasoning to ethics and metaphysics - **Gottfried Wilhelm Leibniz**: Proposed that the mind contains innate principles that structure experience ## Role in [[Philosophy]] & Science - Forms the basis for deductive systems in mathematics and logic - Influences debates about [[Epistemology]], [[free will]], and metaphysics - Provides tools for analyzing moral and theological arguments ## Related Concepts - [[Empiricism]] - [[Skepticism]] - [[Foundationalism]] ## Notable Quotes - "Cogito, ergo sum." — René Descartes - "There are truths of reason and truths of fact." — Gottfried Wilhelm Leibniz - "The order and connection of ideas is the same as the order and connection of things." — Baruch Spinoza