tions,
therefore, of matter are to be regarded as instances of necessary
actions; and whatever is in this respect on the same footing with
matter, must be acknowledged to be necessary. That we may know whether
this be the case with the actions of the mind, we shall begin with
examining matter, and considering on what the idea of a necessity in its
operations are founded, and why we conclude one body or action to be the
infallible cause of another.

It has been observed already, that in no single instance the ultimate
connexion of any objects is discoverable, either by our senses or
reason, and that we can never penetrate so far into the essence and
construction of bodies, as to perceive the principle, on which their
mutual influence depends. It is their constant union alone, with which
we are acquainted; and it is from the constant union the necessity
arises. If objects had nor an uniform and regular conjunction with each
other, we should never arrive at any idea of cause and effect; and even
after all, the necessity, which enters into that idea, is nothing but
a determination of the mind to pass from one object to its usual
attendant, and infer the existence of one from that of the other. Here
then are two particulars, which we are to consider as essential to
necessity, viz, the constant union and the inference of the mind; and
wherever we discover these we must acknowledge a necessity. As the
actions of matter have no necessity, but what is derived from these
circumstances, and it is not by any insight into the essence of bodies
we discover their connexion, the absence of this insight, while
the union and inference remain, will never, in any case, remove the
necessity. It is the observation of the union, which produces the
inference; for which reason it might be thought sufficient, if we prove
a constant union in the actions of the mind, in order to establish the
inference, along with the necessity of these actions. But that I
may bestow a greater force on my reasoning, I shall examine these
particulars apart, and shall first prove from experience that
our actions have a constant union with our motives, tempers, and
circumstances, before I consider the inferences we draw from it.

To this end a very slight and general view of the common course of human
affairs will be sufficient. There is no light, in which we can take
them, that does nor confirm this principle. Whether we consider mankind
according to the differenc