The truth of the doctrine of necessity will be still more evident if we consider the absurdity of the opposite hypothesis. One of its principal ingredients is self-determination. Liberty, in an imperfect and popular sense, is ascribed to the motions of the animal system, when they result from the foresight and deliberation of the intellect, and not from external compulsion. It is in this sense that the word is commonly used in moral and political reasoning. Philosophical reasoners therefore who have desired to vindicate the property of freedom, not only to our external motions, but to the acts of the mind, have been obliged to repeat this process.
Our external actions are then said to be free when they truly result from the determination of the mind. If our volitions, or internal acts, be also free, they must in like manner result from the determination of the mind, or in other words, "the mind in adopting them" must be "self-determined."
Now nothing can be more evident than that in which the mind exercises its freedom must be an act of the mind. Liberty therefore, according to this hypothesis, consists in this, that every choice we make has been chosen by us, and every act of the mind been preceded and produced by an act of the mind. This is so true that, in reality, the ultimate act is not styled free from any quality of its own, but because the mind, in adopting it, was self-determined, that is, because it was preceded by another act. The ultimate act resulted completely from the determination that was its precursor.
It was itself necessary; and, if we would look for freedom, it must be to that preceding act. But, in that preceding act also, if the mind were free, it was self-determined, that is, this volition was chosen by a preceding volition, and, by the same reasoning, this also by another antecedent to itself. All the acts, except the first, were necessary, and followed each other as inevitably as the links of a chain do when the first link is drawn forward. But then neither was this first act free, unless the mind in adopting it were self-determined, that is, unless this act were chosen by a preceding act. Trace back the chain as far as you please, every act at which you arrive is necessary. That act, which gives the character of freedom to the whole, can never be discovered; and, if it could, in its own nature includes a contradiction.
Another idea which belongs to the hypothesis of free will is that the mind is not necessarily inclined this way or that, by the motives which are presented to it, by the clearness or obscurity with which they are apprehended, or by the temper and character which preceding habits may have generated; but that, by its inherent activity, it is equally capable of proceeding either way, and passes to its determination from a previous state of absolute indifference. Now what sort of activity is that which is equally inclined to all kinds of actions? Let us suppose a particle of matter endowed with an inherent propensity to motion. This propensity must either be to move in one particular direction, and then it must for ever move in that direction, unless counteracted by some external impression;Chapter r it must have an equal tendency to all directions, and then the result must be a state of perpetual rest.
The absurdity of this consequence is so evident that the advocates of intellectual liberty have endeavoured to destroy its force, by means of a distinction. "Motive," it has been said, "is indeed the occasion, the sine qua non of volition, but it has no inherent power to compel volition.
Its influence depends upon the free and unconstrained surrender of the mind. Between opposite motives and considerations, the mind can choose as it pleases, and, by its determination, can convert the motive which is weak and insufficient in the comparison into the strongest." But this hypothesis will be found exceedingly inadequate to the purpose for which it is produced. Not to repeat what has been already alleged to prove, that inherent power of production in an antecedent, is, in all cases, a mere fiction of the mind, it may easily be shown, that motives must either have a fixed and certain relation to their consequents, or they can have none.