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The distinction between "primary and secondary qualities," first stated and thus named by Robert Boyle, received its classical formulation in John Locke's Essay. There Locke states that apart from ordinary causal properties or "powers," material objects possess five primary qualities—extension (size), figure (shape), motion or rest, number, and solidity (impenetrability)—and many secondary qualities, such as color, taste, smell, sound, and warmth or cold....
