For first it must be remembered that the ground or reason of any event, of whatever nature it be, must be contained among the circumstances which precede that event. The mind is supposed to be in a state of previous indifference, and therefore cannot be, in itself considered, the source of the particular choice that is made. There is a motive on one side and a motive on the other: and between these lie the true ground and reason of preference.
But, wherever there is tendency to preference, there may be degrees of tendency. If the degrees be equal, preference cannot follow: it is equivalent to the putting equal weights into the opposite scales of a balance. If one of them have a greater tendency to preference than the other, that which has the greatest tendency must ultimately prevail. When two things are balanced against each other, so much amount may be conceived to be struck off from each side as exists in the smaller sum, and the overplus that belongs to the greater is all that truly enters into the consideration.
Add to this, secondly, that, if motive have not a necessary influence, it is altogether superfluous. The mind cannot first choose to be influenced by a motive, and afterwards submit to its operation: for in that case the preference would belong wholly to this previous volition. The determination would in reality be complete in the first instance; and the motive, which came in afterwards, might be the pretext, but could not be the true source of the proceedings.
Lastly, it may be observed upon the hypothesis of free will that the whole system is built upon a distinction where there is no difference, to wit, a distinction between the intellectual and active powers of the mind. A mysterious philosophy taught men to suppose that, when an object was already felt to be desirable, there was need of some distinct power to put the body in motion. But reason finds no ground for this supposition;Chapter or is it possible to conceive (in the case of an intellectual faculty placed in an aptly organized body, where preference exists, together with a sentiment, the dictate of experience) of our power to obtain the object preferred) of anything beyond this that can contribute to render a certain motion of the animal frame the necessary result. We need only attend to the obvious meaning of the terms, in order to perceive that the will is merely, as it has been happily termed, "the last act of the understanding,"