Reason can contribute to knowledge, but only by relating ideas to one another, and ideas are ultimately based on sense impressions. According to this position, rationalist efforts to circumvent the senses by relying on reason alone are bound to fail.

For empiricists, all knowledge is derived from sense experience, and, therefore, the subjective perspectives of observers can never be entirely overcome. Leibniz, for example, provided an account of the world derived by reason from only two basic principles, which he believed were self-evidently true.ĭavid Hume was an exponent of empiricism, a doctrine opposed to rationalism. Because the human senses are inherently fallible, empirical investigations can never reveal how the world really is, untainted by perspective: objective knowledge of the world can be achieved only through the use of reason. According to such rationalists, empirical knowledge based on experience is suspect because it is necessarily tied to the subjective perspectives of individuals. The prevailing philosophical orthodoxy in Kant’s time was a rationalism set out by Gottfried Leibniz (1646-1716), and systematized by Christian Wolff (1679–1750).

To better understand the results of this new line of thought, we should briefly consider the “dogma” in question, and Hume’s attack on it. In one of history’s best-known philosophical compliments, Kant credited the work of David Hume (1711–1776) with disrupting his “dogmatic slumbers” and setting his thinking on an entirely new path. Both of these branches have been enormously influential in the subsequent history of philosophy. The second, his practical philosophy, comprising ethics and political philosophy, is based on the concept of freedom. His theoretical philosophy, which includes metaphysics, is based on the rational understanding of the concept of nature.

The philosophy of Immanuel Kant (1724–1804) can be divided into two major branches.

Kant reason