We infer a cause immediately from its effect; and this inference is not only a true species of reasoning, but the strongest of all others, and more convincing than when we interpose another idea to connect the two extremes.

What we may in general affirm concerning these three acts of the understanding is, that 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.