Unit 3: British Empiricism

The Origin of Knowledge in Experience.

1. John Locke: Rejection of Innate Ideas
2. Primary and Secondary Qualities
3. George Berkeley: Subjective Idealism
4. David Hume: Impressions and Ideas
5. Hume’s Critique of Causality and the Self

1. John Locke: Tabula Rasa

John Locke is the founder of modern empiricism. He argued that the mind is a "Tabula Rasa" (blank slate) at birth.

Sources of Ideas:

Sensation: External experience (perceiving a yellow flower).
Reflection: Internal experience (thinking, doubting, believing).

Locke argued that even our most complex ideas are built from these simple bricks of experience.

2. Primary and Secondary Qualities

To explain the relationship between objects and our minds, Locke distinguished two types of qualities:

Primary Qualities	Secondary Qualities
Exist in the object itself.	Exist only in the mind of the perceiver.
Inseparable from matter (Shape, Motion, Number).	Power of the object to produce sensations (Color, Smell, Taste).
Objective and measurable.	Subjective and variable.

3. George Berkeley: "Esse est Percipi"

Berkeley took Locke's logic further. He argued that if secondary qualities exist only in the mind, then primary qualities (like shape) also exist only in the mind. There is no such thing as "matter."

Subjective Idealism

"Esse est Percipi" (To be is to be perceived). Objects are just collections of ideas. Does a tree exist if no one is there? Yes, because God is the permanent perceiver who holds all ideas in existence.

4. David Hume: Impressions and Ideas

Hume is the most radical empiricist. He divided all mental contents into two categories:

Impressions: Vivid, forceful, and immediate perceptions (actually feeling heat).

Ideas: Faint copies or memories of impressions (thinking about heat later).

Hume’s "Fork": If an idea cannot be traced back to an impression, it is a "sophistry and illusion."

5. Hume’s Skepticism

Hume used his empiricist method to challenge the foundations of human thought:

Causality: We never see "cause," only "constant conjunction" (A happens, then B happens). We believe in cause only out of Custom or Habit.
The Self: When I look inside, I find a bundle of perceptions (pain, cold, happy), but I never find a permanent "Self." The Self is just a "bundle of perceptions."

Knowlet