nce of
number; the other of KIND.

SECT. VI. OF MODES AND SUBSTANCES

I would fain ask those philosophers, who found so much of their
reasonings on the distinction of substance and accident, and imagine we
have clear ideas of each, whether the idea of substance be derived from
the impressions of sensation or of reflection? If it be conveyed to us
by our senses, I ask, which of them; and after what manner? If it be
perceived by the eyes, it must be a colour; if by the ears, a sound; if
by the palate, a taste; and so of the other senses. But I believe none
will assert, that substance is either a colour, or sound, or a taste.
The idea, of substance must therefore be derived from an impression
of reflection, if it really exist. But the impressions of reflection
resolve themselves into our passions and emotions: none of which can
possibly represent a substance. We have therefore no idea of substance,
distinct from that of a collection of particular qualities, nor have we
any other meaning when we either talk or reason concerning it.

The idea of a substance as well as that of a mode, is nothing but a
collection of Simple ideas, that are united by the imagination, and have
a particular name assigned them, by which we are able to recall, either
to ourselves or others, that collection. But the difference betwixt
these ideas consists in this, that the particular qualities, which form
a substance, are commonly referred to an unknown something, in which
they are supposed to inhere; or granting this fiction should not take
place, are at least supposed to be closely and inseparably connected by
the relations of contiguity and causation. The effect of this is, that
whatever new simple quality we discover to have the same connexion with
the rest, we immediately comprehend it among them, even though it did
not enter into the first conception of the substance. Thus our idea of
gold may at first be a yellow colour, weight, malleableness, fusibility;
but upon the discovery of its dissolubility in aqua regia, we join that
to the other qualities, and suppose it to belong to the substance as
much as if its idea had from the beginning made a part of the compound
one. The principal of union being regarded as the chief part of the
complex idea, gives entrance to whatever quality afterwards occurs, and
is equally comprehended by it, as are the others, which first presented
themselves.

That this cannot take place in modes, is evident