2 Rationalism
19.1.2: Rationalism
Rationalism, or a belief that we come to knowledge through the use of logic, and thus independently of sensory experience, was critical to the debates of the Enlightenment period, when most philosophers lauded the power of reason but insisted that knowledge comes from experience.
Learning Objective
Define rationalism and its role in the ideas of the Enlightenment
Key Points
- Rationalism—as an appeal to human reason as a way of obtaining knowledge—has a philosophical history dating from antiquity. While rationalism did not dominate the Enlightenment, it laid critical basis for the debates that developed over the course of the 18th century.
- René Descartes (1596-1650), the first of the modern rationalists, laid the groundwork for debates developed during the Enlightenment. He thought that the knowledge of eternal truths could be attained by reason alone (no experience was necessary).
- Since the Enlightenment, rationalism is usually associated with the introduction of mathematical methods into philosophy as seen in the works of Descartes, Leibniz, and Spinoza. This is commonly called continental rationalism, because it was predominant in the continental schools of Europe, whereas in Britain empiricism dominated.
- Both Spinoza and Leibniz asserted that, in principle, all knowledge, including scientific knowledge, could be gained through the use of reason alone, though they both observed that this was not possible in practice for human beings, except in specific areas, such as mathematics.
- While empiricism (a theory that knowledge comes only or primarily from a sensory experience) dominated the Enlightenment, Immanuel Kant, attempted to combine the principles of empiricism and rationalism. He concluded that both reason and experience are necessary for human knowledge.
- Since the Enlightenment, rationalism in politics historically emphasized a “politics of reason” centered upon rational choice, utilitarianism, and secularism.
Key Terms
- cogito ergo sum
- A Latin philosophical proposition by René Descartes, the first modern rationalist, usually translated into English as “I think, therefore I am.” This proposition became a fundamental element of western philosophy, as it purported to form a secure foundation for knowledge in the face of radical doubt. Descartes asserted that the very act of doubting one’s own existence served, at minimum, as proof of the reality of one’s own mind.
- empiricism
- A theory that states that knowledge comes only, or primarily, from sensory experience. One of several views of epistemology, the study of human knowledge, along with rationalism and skepticism, it emphasizes the role of experience and evidence, especially sensory experience, in the formation of ideas over the notion of innate ideas or traditions.
- metaphysics
- A traditional branch of philosophy concerned with explaining the fundamental nature of being and the world that encompasses it, although the term is not easily d