Introduction to Philosophy

12 February 2001

I. Locke

A. Rationalism vs Empiricism

B. Ideas vs qualities

1. Idea: whatsoever the mind perceives in itself, or is the immediate object of perception, thought, or understanding

2. Quality: The power to produce any idea in our mind

C. Primary, secondary, and tertiary qualities

1. Primary qualities (a.k.a. ‘original’ qualities; sometimes ‘real’ qualities)

a. “such as are utterly inseparable from the body, in what estate soever it be; and such as in all the alterations and changes it suffers, all the force can be used upon it, it constantly keeps; and such as sense constantly finds in every particle of matter which has bulk enough to be perceived; and the mind finds inseparable from every particle of matter, though less than to make itself singly be perceived by our senses….”

b. Examples: solidity, extension, figure, motion or rest, and number. (Also, sometimes, bulk and texture).

2. Secondary qualities (also, ‘sensible qualities’)

a. “such qualities which in truth are nothing in the objects themselves but powers to produce various sensations in us…as colours, sounds, tastes, etc.”

b. Systematically illusory

3. Tertiary qualities (also, ‘secondary qualities mediately perceivable’ or just ‘powers’)

a. Powers of objects to produce changes in the primary qualities of other bodies

b. Example: power of the sun (or of fire) to produce a new shape or size in wax.

D. Epistemological significance of the distinction

II. Berkeley

A. Reaction to Locke’s dualism of idea and quality

B. Epistemological argument for a metaphysical position

1. Extension of skepticism, assuming Locke’s dualism

2. But, repugnance of skepticism

3. Rejection of Locke’s dualism