a sufficient number of experiments, rest contented with that, when he
sees a farther examination would lead him into obscure and uncertain
speculations. In that case his enquiry would be much better employed in
examining the effects than the causes of his principle.

Amongst the effects of this union or association of ideas, there are none
more remarkable, than those complex ideas, which are the common subjects
of our thoughts and reasoning, and generally arise from some principle of
union among our simple ideas. These complex ideas may be divided into
Relations, Modes, and Substances. We shall briefly examine each of these
in order, and shall subjoin some considerations concerning our general
and particular ideas, before we leave the present subject, which may be
considered as the elements of this philosophy.



SECT. V. OF RELATIONS.


The word RELATION is commonly used in two senses considerably different
from each other. Either for that quality, by which two ideas are
connected together in the imagination, and the one naturally introduces
the other, after the manner above-explained: or for that particular
circumstance, in which, even upon the arbitrary union of two ideas in the
fancy, we may think proper to compare them. In common language the former
is always the sense, in which we use the word, relation; and it is only in
philosophy, that we extend it to mean any particular subject of
comparison, without a connecting principle. Thus distance will be allowed
by philosophers to be a true relation, because we acquire an idea of it
by the comparing of objects: But in a common way we say, THAT NOTHING CAN