Motives, as they are called, are different from each other in nature and in kind; and hence, it were absurd to compare them in degree. "The strongest motive," therefore, is a mode of expression which can have no intelligible meaning, unless it be used with reference to the influence which motives are supposed to exert over the mind. This is the sense in which it clearly seems to be used by Edwards. The distinguishing property of a motive, according to his definition, is nothing in the nature of the motive itself; it consists in its adaptedness "to move or excite the mind to volition;" nor indeed could he find any other way of measuring or determining what he calls the strength of motives, since they are so diverse in their own nature from each other. He could not have given any plausible definition of the strength of motives, if he had looked at them as they are in themselves; and hence, he was under the necessity of defining it, by a reference to the "degree of tendency or _advantage_ they have to move or excite the will." Thus, according to the Inquiry, the will is determined by the strongest motive; and yet we can form no intelligible idea of what is meant by the strongest motive, unless we conceive it to be that which determines the will. The matter will not be mended, by alleging that the strongest motive is not defined to be that which actually determines the will, but that which has the greatest degree of previous tendency or advantage, to excite or move it; for we cannot know what motive has this greatest degree of previous tendency or advantage, except by observing what motive actually does determine the will. This leads us to another view of the same subject. The strength of a motive, as President Edwards properly remarks, depends upon the state of the mind to which it is addressed. Hence, in a great majority of cases, we can know nothing about the relative strength of motives, except from the actual influence which they exert over the mind of the individual upon whom they are brought to bear. This shows that the universal proposition, that the will is _always_ determined by the strongest motive, can be known to be true, only by assuming that the strongest motive is that by which the will is determined.