Locke's Primary vs Secondary Qualities Explained

John Locke identified two main categories of qualities inherent in objects:

Primary Qualities Defined

• These are qualities inherent in the object itself, existing independently of any observer.
• They are inseparable from the object.
• Examples include: $solidity$ (or $impenetrability$), $extension$ (size, shape, space occupied), $figure$, $motion$ or $rest$, and $number$.

Secondary Qualities Defined

• These are powers within objects that produce sensations in us (the observer) via their primary qualities.
• They are not inherent in the object itself but depend on the interaction with the perceiver's senses.
• Examples include: $colour$, $sound$, $smell$, $taste$, and $texture$ (like $smoothness$ or $roughness$).

Analyzing Locke's Distinction in Options

We examine each option to see which best matches Locke's definitions:

• Option 1: Incorrect. Lists $colour$ (secondary) as primary and $shape$, $mobility$, $hardness$ (all primary) as secondary.
• Option 2: Correct. Lists $number$, $extension$, $mobility$ as primary qualities and $smell$, $colour$, $smoothness$ as secondary qualities, aligning perfectly with Locke's categories.
• Option 3: Incorrect. Includes $roughness$ and $colour$ (secondary) under primary qualities.
• Option 4: Incorrect. Includes $sound$ (secondary) as primary and miscategorizes $impenetrability$.

Option 2 provides the correct exemplification of John Locke's distinction between primary and secondary qualities.