does occupy, or act in any other place than it does act. The idea of necessity is obtained by our experience of the connection between objects, the uniformity of the operations of nature, the constant conjunction of similar events, and the consequent inference of one from the other. Mankind are therefore agreed in the admission of necessity, if they admit that these two circumstances take place in voluntary action. Motive is, to voluntary action in the human mind, what cause is to effect in the material universe. The word liberty, as applied to mind, is analogous to the word chance, as applied to matter: they spring from an ignorance of the certainty of the conjunction of antecedents and consequents.
Every human being is irresistibly impelled to act precisely as he does act: in the eternity which preceded his birth, a chain of causes was generated, which, operating under the name of motives, make it impossible that any thought of his mind, or any action of his life, should be otherwise than it is. Were the doctrine of Necessity false, the human mind would no longer be a legitimate object of science; from like causes it would be in vain that we should expect like effects; the strongest motive would no longer be paramount over the conduct; all knowledge would be vague and undeterminate; we could not predict with any certainty, that we might not meet as an enemy to-morrow, him with whom we have parted in friendship to-night; the most probable inducements and the clearest reasonings would lose the invariable influence they possess. The contrary of this is demonstrably the fact.
