taking them in a proper
light, they all resolve themselves into the first, and are nothing but
particular ways of conceiving our objects. Whether we consider a single
object, or several; whether we dwell on these objects, or run from them
to others; and in whatever form or order we survey them, the act of
the mind exceeds not a simple conception; and the only remarkable
difference, which occurs on this occasion, is, when we join belief to
the conception, and are persuaded of the truth of what we conceive.
This act of the mind has never yet been explaind by any philosopher; and
therefore I am at liberty to propose my hypothesis concerning it; which
is, that it is only a strong and steady conception of any idea, and such
as approaches in some measure to an immediate impression. [Footnote 5.]

[Footnote 5. Here are the heads of those arguments, which
lead us to this conclusion. When we infer the existence of
an object from that of others, some object must always be
present either to the memory or senses, in order to be the
foundation of our reasoning; since the mind cannot run up
with its inferences IN INFINITUM. Reason can never satisfy
us that the existence of any one object does ever imply that
of another; so that when we pass from the impression of one
to the idea or belief of another, we are not determined by
reason, but by custom or a principle of association. But
belief is somewhat more than a simple idea. It is a
particular manner of forming an idea: And as the same idea
can only be varyed by a variation of its degrees of force
and vivacity; it follows upon the whole, that belief is a
lively idea produced by a relation to a present impression,
according to the foregoing definition.]

This operation of the mind, which forms the belief of any matter of
fact, seems hitherto to have been one of the greatest mysteries of
philosophy; though no one has so much as suspected, that there was
any difficulty in explaining it. For my part I must own, that I find
a considerable difficulty in the case; and that even when I think I
understand the subject perfectly, I am at a loss for terms to express
my meaning. I conclude, by an induction which seems to me very evident,
that an opinion or belief is nothing but an idea, that is different
from a fiction, not in the nature or the order of its parts, but in the
manner of its being conceived. But when