consequence that belief,
which arises from it. The vivacity of the first impression cannot be
fully conveyed to the related idea, either where the conjunction of
their objects is not constant, or where the present impression does
not perfectly resemble any of those, whose union we are accustomed to
observe. In those probabilities of chance and causes above-explained,
it is the constancy of the union, which is diminished; and in the
probability derived from analogy, it is the resemblance only, which is
affected. Without some degree of resemblance, as well as union, it is
impossible there can be any reasoning: but as this resemblance admits
of many different degrees, the reasoning becomes proportionably more
or less firm and certain. An experiment loses of its force, when
transferred to instances, which are not exactly resembling; though it
is evident it may still retain as much as may be the foundation of
probability, as long as there is any resemblance remaining.

SECT. XIII. OF UNPHILOSOPHICAL PROBABILITY.

All these kinds of probability are received by philosophers, and allowed
to be reasonable foundations of belief and opinion. But there are
others, that are derived from the same principles, though they have not
had the good fortune to obtain the same sanction. The first probability
of this kind may be accounted for thus. The diminution of the union, and
of the resemblance, as above explained, diminishes the facility of the
transition, and by that means weakens the evidence; and we may farther
observe, that the same diminution of the evidence will follow from a
diminution of the impression, and from the shading of those colours,
under which it appears to the memory or senses. The argument, which
we found on any matter of fact we remember, is more or less convincing
according as the fact is recent or remote; and though the difference
in these degrees of evidence be not received by philosophy as solid and
legitimate; because in that case an argument must have a different force
to day, from what it shall have a month hence; yet notwithstanding
the opposition of philosophy, it is certain, this circumstance has a
considerable influence on the understanding, and secretly changes the
authority of the same argument, according to the different times,
in which it is proposed to us. A greater force and vivacity in the
impression naturally conveys a greater to the related idea; and it is on
the degrees of force and viva