e is so inconsiderable. We have a
parallel instance in the affections. It is evident, according to the
principles above-mentioned, that when an object produces any passion in
us, which varies according to the different quantity of the object; I
say, it is evident, that the passion, properly speaking, is not a simple
emotion, but a compounded one, of a great number of weaker passions,
derived from a view of each part of the object. For otherwise it were
impossible the passion should encrease by the encrease of these parts.
Thus a man, who desires a thousand pound, has in reality a thousand
or more desires which uniting together, seem to make only one passion;
though the composition evidently betrays itself upon every alteration of
the object, by the preference he gives to the larger number, if superior
only by an unite. Yet nothing can be more certain, than that so small
a difference would not be discernible in the passions, nor coued render
them distinguishable from each other. The difference, therefore, of our
conduct in preferring the greater number depends not upon our passions,
but upon custom, and general rules. We have found in a multitude of
instances, that the augmenting the numbers of any sum augments the
passion, where the numbers are precise and the difference sensible. The
mind can perceive from its immediate feeling, that three guineas produce
a greater passion than two; and this it transfers to larger numbers,
because of the resemblance; and by a general rule assigns to a thousand
guineas, a stronger passion than to nine hundred and ninety nine. These
general rules we shall explain presently.

But beside these two species of probability, which a-re derived from an
imperfect experience and from contrary causes, there is a third arising
from ANALOGY, which differs from them in some material circumstances.
According to the hypothesis above explained all kinds of reasoning from
causes or effects are founded on two particulars, viz., the constant
conjunction of any two objects in all past experience, and the
resemblance of a present object to any one of them. The effect of these
two particulars is, that the present object invigorates and inlivens the
imagination; and the resemblance, along with the constant union, conveys
this force and vivacity to the related idea; which we are therefore said
to believe, or assent to. If you weaken either the union or resemblance,
you weaken the principle of transition, and of