John Locke (1632–1704), the noted English philosopher, scientist, and political theorist, was one of the leading intellectuals of his age and one of the most influential architects of the modern western world. Like his French counterpart René Descartes, Locke came from a respected family and did well in school, directing his studies at Oxford University for a career as a physician. But Locke’s interests were much broader than medicine, and with the assistance of influential friends such as Lord Shaftesbury, he was appointed to a series of governmental positions following the English Civil War and the Glorious Revolution of 1688–1689 that brought William of Orange and Mary to the throne. In his Two Treatises of Civil Government (1690), Locke argued against the Divine Right Theory and began to formulate and espouse a liberal political philosophy based on the notions of natural rights, limited government, and the legitimate right of people to rebel against tyranny.
But although Locke may be best known for his political theories, he was also deeply interested in epistemology and the ways in which people acquire knowledge. In his “Essay Concerning Human Understanding” (1690), Locke expressed frustration with overly abstract forms of thought, which he believed only yielded meaningless and futile discussions of truth and reality. Instead, Locke argued that all knowledge was based on data acquired by the dual process of sensory experience (what he called “sensation”) and subsequent mental thought and analysis (“reflection”). By stressing the importance of observation, the collection of evidence, and inductive reasoning, Locke defined a mode of inquiry called empiricism, which became the foundation for the scientific method so important to the discoveries and technological innovations of the modern world.
In the reading that follows, Locke carefully advances his new theory of human understanding. He begins with his statement of purpose, which he claims is to know and understand the limits of human knowledge. He then proceeds to explain his ideas of “sensation” and “reflection,” as well as his assertion that people are born lacking all innate ideas.
John Locke, The Works of John Locke, a New Edition, Corrected, Vol. 1 (London: Thomas Tegg, 1823): 1–2, 13, 82–84, 86–87, 90–91, 96–98, 99–103, 153–54.