John Locke (1632–1704) founded British Empiricism by attacking the Rationalist belief in Innate Ideas (ideas allegedly present in the mind from birth).
Locke argued that at birth, the mind is a Tabula Rasa—a blank slate. All knowledge comes from Experience, which has two sources:
"Nothing is in the intellect which was not first in the senses."
Locke’s theory of knowledge is called Representationalism or the Mediate Theory of Perception. He argues that the mind does not perceive external objects directly, but only the ideas (mental representations) of those objects.
| Feature | Primary Qualities | Secondary Qualities |
|---|---|---|
| Definition | Inseparable from the object. | Powers to produce sensations in us. |
| Objectivity | Objective (really in the object). | Subjective (depend on the observer). |
| Examples | Shape, Size, Motion, Number. | Color, Sound, Taste, Smell. |
Berkeley (1685–1753) accepted Locke’s empiricism but rejected his belief in material substance, leading to Subjective Idealism.
"Esse est Percipi" — To be is to be perceived.
Berkeley argued that if secondary qualities (like color) are subjective, primary qualities (like shape) must also be subjective, as we cannot imagine a shape without color. Therefore, "matter" does not exist; only minds and ideas exist.
If objects only exist when perceived, why don't things disappear when we close our eyes? Berkeley answers that God is the permanent perceiver who keeps all ideas in existence.
Hume (1711–1776) carried empiricism to its logical extreme, resulting in Skepticism.
Hume divides all mental contents into two categories:
Hume famously argued that we have no impression of "Cause" or "Self". We only see one event following another (contiguity) and develop a habit of expecting the effect, but there is no logical or sensory proof of Necessary Connection.
"Custom is the great guide of human life."
Locke: Limited (Matter exists but we only see ideas).
Berkeley: Banished (Matter is banished; only ideas exist).
Hume: Havoc (Doubted everything; skepticism).
Q: Why does Hume reject the 'Self'?
A: He says when he looks inside, he finds only a "bundle of perceptions" (heat, cold, light, shade) but never a permanent "Self".
Q: What is the 'Missing Shade of Blue'?
A: A rare exception Hume admits where an idea might be formed without a direct preceding impression.