John Locke (1632-1704) stands as the intellectual apostle of the Glorious Revolution of 1688, a pivotal event in English history that established a more moderate and successful form of parliamentary democracy.
His philosophical works, particularly the monumental Essay Concerning Human Understanding, faithfully embody the spirit of this revolution, advocating for a philosophy grounded in experience and reason, rather than innate ideas or unquestioned authority. Locke’s influence on both theoretical philosophy (as the founder of empiricism) and political thought (as the founder of philosophical liberalism) was immense and enduring.
At the core of Locke’s theory of knowledge is his radical rejection of innate ideas and principles. Against the prevailing views of Plato, Descartes, and the Scholastics, Locke famously asserted that the mind is a “tabula rasa” (white paper) at birth, void of all characters and ideas.
All our knowledge, he argued, is derived from experience. This experience comes from two primary sources: sensation (our perception of external objects) and reflection (our perception of the operations of our own mind, or “internal sense”). This complete dependence of knowledge upon perception was a revolutionary doctrine for his time, challenging centuries of philosophical tradition that had emphasized a priori knowledge.
💡 Primary vs. Secondary Qualities: A Useful Distinction?
Locke introduced the influential distinction between primary and secondary qualities. Primary qualities (like solidity, extension, figure, motion/rest, and number) are those that are inseparable from bodies and are actually present in external objects.
Secondary qualities (like color, sound, smell, and taste), on the other hand, are merely powers in objects to produce sensations in us and exist only in the percipient mind.
While this distinction has since been philosophically challenged (notably by George Berkeley, who argued that the same arguments applied to primary qualities), it proved immensely fruitful for the development of practical physics. It provided a framework for understanding the physical world as consisting primarily of matter in motion, which became the basis for accepted theories of sound, heat, light, and electricity, demonstrating the pragmatic utility of Locke’s doctrines.
⚖️ Reason, Revelation, and the Limits of Knowledge
A key characteristic of Locke’s philosophy, which profoundly influenced the entire Liberal movement, is his lack of dogmatism. While he accepted certainties like his own existence, the existence of God, and the truth of mathematics, he approached other doctrines with a degree of doubt.
He believed that reason should ultimately judge revelation, asserting that “the bare testimony of revelation is the highest certainty,” but also, crucially, “Revelation must be judged by reason.” This emphasis on reason as the supreme arbiter, even over professed revelations, is evident in his critique of “enthusiasm” (the belief in personal, ungrounded revelations).
Locke argued that the degree of assent given to any proposition should depend on the evidence supporting it, which led him to advocate for mutual charity and forbearance in the face of differing opinions.
While his theory of knowledge faced logical inconsistencies (particularly in explaining how we know of an external world if our knowledge is confined to our own ideas), Locke’s commitment to empiricism, his pragmatic approach, and his undogmatic temper laid essential groundwork for subsequent philosophical inquiry and the development of modern scientific thought.
Source: Russell, Bertrand. A History of Western Philosophy. Simon and Schuster, 1945.
More Topics
- John Dewey: Instrumentalism and the Evolution of Truth
- The Utilitarians: Can Happiness Be Quantified and Legislated?
- Karl Marx: The Philosopher of History, Class, and Revolution
- Bergson: The Philosopher of Life, Intuition, and Creative Evolution
- William James: Radical Empiricism and the ‘Will to Believe’
- Locke’s Political Philosophy: How Did He Justify Government by Consent?
- Schopenhauer: The Philosopher of Will, Suffering, and Pessimism
