One reason why the advocates of necessity deceive themselves, as well as others, is, that there is great want of precision and distinctness in their views and definitions. We are told by them that the will is always determined by the strongest motive; that this is invariably the cause of volition. But what is meant by the term _cause_? We have final causes, instrumental causes, occasional causes, predisposing causes, efficient causes, and many others. Now, in which of these senses is the word used, when we are informed that motive is the cause of volition? On this point we are not enlightened. Neither Leibnitz nor Edwards is sufficiently explicit. The proposition, as left by them, is vague and obscure. Leibnitz inclined to the use of the word _reason_, because he carried on a controversy with Bayle and Hobbes, who were atheists; though he frequently speaks of a chain of causes which embrace human volitions.(121) While Edwards, who opposed the Arminians, generally employs the more rigid term _cause_; though he, too, frequently represents motive as “the ground and reason” of volition. The one softens his language, in places, as he contends with those who had rendered themselves obnoxious to the Christian world by an advocacy of the doctrine of necessity in connexion with atheistical sentiments. The other appears to prefer the stronger expression, as he puts forth his power against antagonists whose views of liberty were deemed subversive of the tenets of Calvinism. But the law of causality, as stated by Edwards, and the principle of the sufficient reason, as defined and employed by Leibnitz, are perfectly identical. When we are told that motive is the cause of volition, it is evident we cannot determine whether to deny or to assent to the proposition, unless we know in what sense the term _cause_ is used. We might discuss this perplexed question forever, by the use of such vague and indefinite propositions, without progressing a single step toward the end of the controversy. We must bring a more searching analysis to the subject, if we hope to accomplish anything. We must take the word cause or _reason_, in each of its significations, in order to discover in what particulars the contending parties agree, and in what particulars they disagree, in order to see how far each party is right, and how far it is wrong. This is the only course that promises the least prospect of a satisfactory result.