Rationalism
True knowledge comes from reason alone, independent of sensory experience.
Overview
Rationalists argued that the most important truths — mathematical, logical, and metaphysical — can be known through pure reason, without relying on the senses. Our senses can deceive us (optical illusions, hallucinations, dreams), but logical truths cannot be false. The mind possesses innate ideas or principles that provide the foundation for genuine knowledge. Reason, not experience, is the ultimate authority.
Origins
Early modern rationalism emerged in the 17th century as Descartes, shaken by skeptical challenges, sought an unshakable foundation for knowledge. His method of radical doubt — systematically questioning everything until he reached the indubitable 'I think, therefore I am' — launched a philosophical revolution. Spinoza and Leibniz extended this confidence in reason into comprehensive metaphysical systems.
Key Thinkers (3)
René Descartes
1596 CE – 1650 CE
Systematic doubt reveals one indubitable truth: I think, therefore I am.
Baruch Spinoza
1632 CE – 1677 CE
God and Nature are one infinite substance; freedom comes through understanding necessity.
Gottfried Wilhelm Leibniz
1646 CE – 1716 CE
This is the best of all possible worlds; reality consists of infinite simple substances called monads.