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.
themselves.

That this cannot take place in modes, is evident from considering their
mature. The. simple ideas of which modes are formed, either represent
qualities, which are not united by contiguity and causation, but are
dispersed in different subjects; or if they be all united together, the
uniting principle is not regarded as the foundation of the complex idea.
The idea of a dance is an instance of the first kind of modes; that of
beauty of the second. The reason is obvious, why such complex ideas
cannot receive any new idea, without changing the name, which
distinguishes the mode.



SECT. VII. OF ABSTRACT IDEAS.


A very material question has been started concerning ABSTRACT or GENERAL
ideas, WHETHER THEY BE GENERAL OR PARTICULAR IN THE MIND'S CONCEPTION OF