e connexion of the ideas is not habitual
after one experiment: but this connexion is comprehended under another
principle, that is habitual; which brings us back to our hypothesis. In
all cases we transfer our experience to instances, of which we have no
experience, either expressly or tacitly, either directly or indirectly.

I must not conclude this subject without observing, that it is very
difficult to talk of the operations of the mind with perfect propriety
and exactness; because common language has seldom made any very nice
distinctions among them, but has generally called by the same term
all such as nearly resemble each other. And as this is a source
almost inevitable of obscurity and confusion in the author; so it may
frequently give rise to doubts and objections in the reader, which
otherwise he would never have dreamed of. Thus my general position, that
an opinion or belief is nothing but a strong and lively idea derived
from a present impression related to it, maybe liable to the following
objection, by reason of a little ambiguity in those words strong and
lively. It may be said, that not only an impression may give rise to
reasoning, but that an idea may also have the same influence; especially
upon my principle, that all our ideas are derived from correspondent
impressions. For suppose I form at present an idea, of which I have
forgot the correspondent impression, I am able to conclude from this
idea, that such an impression did once exist; and as this conclusion is
attended with belief, it may be asked, from whence are the qualities of
force and vivacity derived, which constitute this belief? And to this I
answer very readily, from the present idea. For as this idea is not here
considered, as the representation of any absent object, but as a real
perception in the mind, of which we are intimately conscious, it must
be able to bestow on whatever is related to it the same quality, call
it firmness, or solidity, or force, or vivacity, with which the mind
reflects upon it, and is assured of its present existence. The idea here
supplies the place of an impression, and is entirely the same, so far as
regards our present purpose.

Upon the same principles we need not be surprized to hear of the
remembrance of an idea: that is, of the idea of an idea, and of its
force and vivacity superior to the loose conceptions of the imagination.
In thinking of our past thoughts we not only delineate out the objects,
of whi