Motion in one body in all past instances, that have fallen under our observation, is followed upon impulse by motion in another.

It is impossible for the mind to penetrate farther.

From this constant union it forms the idea of cause and effect, and by its influence feels the necessity.

As there is the same constancy, and the same influence in what we call moral evidence, I ask no more.

What remains can only be a dispute of words.
And indeed, when we consider how aptly natural and moral evidence cement together, and form only one chain of argument betwixt them, we shall make no scruple to allow, that they are of the same nature, and derived from the same principles.