Proceeding then in that reasoning, wherein we have advanced three steps;
that chance is merely the negation of a cause, and produces a total
indifference in the mind; that one negation of a cause and one total
indifference can never be superior or inferior to another; and that
there must always be a mixture of causes among the chances, in order to
be the foundation of any reasoning: We are next to consider what effect
a superior combination of chances can have upon the mind, and after what
manner it influences our judgment and opinion. Here we may repeat all
the same arguments we employed in examining that belief, which arises
from causes; and may prove, after the same manner, that a superior
number of chances produces our assent neither by demonstration nor
probability. It is indeed evident that we can never by the comparison
of mere ideas make any discovery, which can be of consequence in this
affairs and that it is impossible to prove with certainty, that any
event must fall on that side where there is a superior number of
chances. To, suppose in this case any certainty, were to overthrow what
we have established concerning the opposition of chances, and their
perfect equality and indifference.
Should it be said, that though in an opposition of chances it is
impossible to determine with certainty, on which side the event will
fall, yet we can pronounce with certainty, that it is more likely and
probable, it will be on that side where there is a superior number of
chances, than where there is an inferior: should this be said, I would
ask, what is here meant by likelihood and probability? The likelihood
and probability of chances is a superior number of equal chances; and
consequently when we say it is likely the event win fall on the side,
which is superior, rather than on the inferior, we do no more than
affirm, that where there is a superior number of chances there is
actually a superior, and where there is an inferior there is an
inferior; which are identical propositions, and of no consequence. The
question is, by what means a superior number of equal chances operates
upon the mind, and produces belief or assent; since it appears, that
it is neither by arguments derived from demonstration, nor from
probability.