John Locke, George Berkeley, and David Hume: Empiricism
John Locke (1632-1704)
Early Influences and Studies
Locke’s interest in philosophy was awakened after reading Descartes, who would have a great influence on him. He studied not only philosophy, but also physics, chemistry, and medicine. He was an advocate of liberal ideals and free thinking.
Locke’s Works: Origin of Ideas
Locke’s fundamental assertion is that all our ideas come from experience. The central question is how these ideas arise—in other words, how the human mind acquires ideas and what psychological mechanisms are involved. Locke’s doctrine is often called psychological.
What is an Idea?
For Locke, an idea is “everything we know or perceive.” Ideas can be:
- Simple ideas: These are immediate sensations like color or smell. They can come from:
- Senses (external experience)
- Primary qualities (size, shape)
- Secondary qualities (odor, color)
- Reflection (inner experience): The mind’s knowledge of its own actions
- Complex ideas: These are produced by the human mind by thinking, relating, and combining simple ideas. The understanding is active in developing these ideas (unlike with simple ideas, where it is passive). Because we can know nothing of the substance of the soul or God, this will lead to Hume’s skepticism.
George Berkeley (1685-1753)
Building on Locke
Berkeley took Locke’s key findings and, noting inconsistencies, attempted to draw new conclusions. Locke stated that an idea is everything we perceive or know, meaning we only know ideas, which are representations of “external” qualities. Berkeley countered: If we don’t know external reality but only the idea, how can we claim the idea represents that reality? Therefore, we only know ideas, and there are no things outside the mind. The only reality is the mind that perceives them.
David Hume (1711-1776)
Life and Works
Born in Edinburgh in 1711, Hume retreated to France in 1734, where he wrote his first book, A Treatise of Human Nature. His other works include An Enquiry Concerning Human Understanding.
Hume’s Problem
In his Treatise, Hume sought to contribute to the advancement of knowledge based on certainty. He believed this could only be achieved by building a science of human nature, the only true science of man. This “knowledge” requires studying human cognition: its scope, validity, and the potential for knowledge. The nature of ideas must also be studied, as our knowledge is founded on them. Hume advocated for a new foundation based solely on experience and observation. Understanding must be limited to the realm of human experience; we cannot go beyond it.
Knowledge in Hume: Impressions and Ideas
Locke defined an idea as “whatever we know or perceive.” Hume refined this, dividing the contents of knowledge into two classes:
- Impressions: Knowledge through the senses.
- Ideas: Representations or copies of impressions in thought. For example, perceiving a classroom (walls, blackboard, tables) and then closing one’s eyes and imagining it—the first is an impression, the second an idea. Impressions are all our feelings, while ideas are faint images of impressions.
Both impressions and ideas can be:
- Simple: Having no distinction or separation (e.g., the color blue and the idea of blue). These have the most cognitive value.
- Complex: Admitting distinctions within them (e.g., a classroom scene).