Primary, Secondary and Bare Qualities

Qualities of bodies = Powers possessed by bodies.

(However, Locke doesn't refer to primary qualities as powers.)

(I) Primary Qualities

(a) Primary qualities: qualities in atoms, and hence, qualities in bodies, e.g. size, extension, shape, movement, solidity, number

Primary qualities: powers in bodies to produce ideas in our minds of e.g. size, extension, shape, movement, solidity, number.

(b) Ideas of primary qualities: e.g., extension, shape, movement, solidity, number.

Ideas of primary qualities of bodies 'resemble' primary qualities in objects/bodies, i.e. idea of size 'resembles' size in a body.

Ideas of secondary qualities do not resemble secondary qualities, i.e. idea of color does not resemble 'color' in a body (no such thing as 'color' in a body), and it doesn't resemble the power to produce the idea of color either

(II) Secondary qualities

(a) Secondary qualities: powers in bodies to produce ideas in our minds of e.g. hot, cold, sound, color, taste, smell.

Question: are secondary qualities "in" bodies?

(i) No: Hot, cold, color, etc., are not in bodies.
(ii) Yes: the powers are in bodies.

(b) Ideas of secondary qualities: e.g., heat, coldness, color, taste, smell.

(III) Bare Powers

(a) Bare powers: powers in bodies to affect other bodies, e.g. melting, fading.

Question: are powers in bodies?

(i) No: Melting, fading, etc., are not in bodies.
(ii) Yes: the powers are in bodies.


(b) Ideas of powers: e.g., melting, fading.


Ideas of powers do not resemble powers, i.e. idea of melting does not resemble 'melting' in a body (no such thing as 'melting' in a body), and it doesn't resemble the power to produce the melting either.