Philosophy 224 - 12.1.1 Rationalism and Empiricism

Enlightenment thinkers proposed that the knowledge needed to improve social conditions could be gathered through rationalism, which regards reason as the source of most knowledge, and empiricism, which relies upon the evidence provided by experiments. The French thinker René Descartes (1596–1650) argued that true knowledge could be acquired through reason alone, without relying on experience. Descartes’s famous quote “I think therefore I am” insists that we know what we know due to abstract reason. For example, knowing that one plus one equals two is a function of reason rather than personal experience.

Other Enlightenment thinkers, including the English philosophers Francis Bacon (1561–1626) and John Locke (1632–1704), believed that knowledge could be gained only through empirical methods, including direct and indirect observation and experience. According to these thinkers, we make deductions from observations that suggest patterns or connection. These deductions can then be tested by systematically observing further phenomena and recording and analyzing data surrounding these phenomena. The scientific method is an empirical method solidified during the Enlightenment period that has become the standard way of conducting any type of objective research.

While rationalism and empiricism seem to be making opposing claims about truth, each has value, and the two can work together. The technological advances of the last 200 years—such as the launching of astronauts into space; the invention of radio, television, and the internet; and the eradication of diseases such as polio—can be said to be the result of both rationalism and empiricism.


To learn more about the ideas of Descartes and the empiricists, visit the chapter on epistemology and the chapter on logic and reason.

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The content of this course has been taken from the free Philosophy textbook by Openstax