In philosophy, David Hume is considered an empiricist, believing that knowledge is based on experimentation and observation through our senses. Throughout A Treatise of Human Nature, Hume not only presents his empiricist view of human knowledge, but also criticizes the rationalist tradition in Western philosophy. This tradition arguably started with the ancient Greek philosopher Plato, who argued that abstract reason gives an even better impression of reality than the impressions gained through our senses. Rationalism also had a powerful advocate in the 17th-century French philosopher René Descartes, who argued that a person is born already knowing several abstract concepts. Descartes and other rationalists also argued that the superior way of gaining knowledge is through logical deduction or abstract reasoning.

Empirical philosophers like Hume instead suggest that knowledge through the senses is the better—or even the only—way to develop knowledge. Through the influence of philosophers like Hume, empiricism would become the dominant philosophy of the Enlightenment. The mainstream thought of the Enlightenment would emphasize scientific observation and material experience over abstract reasoning and metaphysical topics like the nature of the soul. Enlightenment thought would follow Hume’s path by questioning the idea that laws and even morals can be rationalized through some kind of natural, universal law that can only be understood through abstract reasoning.