— 134 —
Primary and Secondary Qualities.       §9. Qualities thus considered in Bodies are, First such as are
utterly inseparable from the Body, in what estate soever it be; 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
— 135 —
perceived, and the Mind finds inseparable from every particle of
Matter, though less than to make it self singly be perceived by our
Senses. v.g. Take a grain of Wheat, divide it into two parts, each
part has still Solidity, Extension, Figure, and Mobility; divide it again,
and it retains still the same qualities; and so divide it on, till the
parts become insensible, they must retain still each of them all
those qualities. For division (which is all that a Mill, or Pestel, or
any other Body, does upon another, in reducing it to insensible
parts) can never take away either Solidity, Extension, Figure, or
Mobility from any Body, but only makes two, or more distinct
separate masses of Matter, of that which was but one before, all
which distinct masses, reckon’d as so many distinct Bodies, after
division make a certain Number. These I call original or primary
Qualities of Body, which I think we may observe to produce simple
Ideas in us, viz. Solidity, Extension, Figure, Motion, or Rest, and
Number.
Locke Hum II, 8, §9, pp. 134-135