bethink himself what reason he has to say
that his idea of warmth, which was produced in him by the fire,
is actually in the fire; and his idea of pain which the same fire
produced in him in the same way, is not in the fire. Why are whiteness
and coldness in snow, and pain not, when it produces the one and the
other idea in us; and can do neither but by the bulk, figure, number,
and motion of its solid parts?"[1]

[Footnote 1: Locke, "Human Understanding," Book II. chap. viii. Sec.Sec. 14,
15.]

Thus far then materialists and idealists are agreed. Locke and
Berkeley, and all logical thinkers who have succeeded them, are of
one mind about secondary qualities--their being is to be perceived or
known--their materiality is, in strictness, a spirituality.

But Locke draws a great distinction between the secondary qualities of
matter, and certain others which he terms "primary qualities." These
are extension, figure, solidity, motion and rest, and number; and he
is as clear that these primary qualities exist independently of the
mind, as he is that the secondary qualities have no such existence.

"The particular bulk, number, figure, and motion of the parts
of fire and snow are really in them, whether anyone's senses
perceive them or not, and therefore they may be called real
qualities, because they really exist in those bodies; but
light, heat, whiteness, or coldness, are no more really in
them, than sickness, or pain, is in manna. Take away the
sensation of them; let not the eyes see light or colours, nor
the ears hear sounds; let the palate not taste, nor the nose
smell; and all colours, tastes, odours and sounds, as they are
such particular ideas, vanish and cease, and are reduced to
their causes, i.e. bulk, figure, and motion of parts.

"18. A piece of manna of sensible bulk is able to produce in
us the idea of a round or square figure; and, by being removed
from one place to another, the idea of motion. This idea of
motion represents it as it really is in the manna moving; a
circle and square are the same, whether in idea or existence,
in the mind or in the manna; and thus both motion and figure
are really in the manna, whether we take notice of them or no:
this everybody is ready to agree to."

So far as primary qualities are concerned, then, Locke is as
thoroughgoing a realist as St. Anselm. In Berkeley, on the other
hand, we have as