Edwards, in contemplating and urging the absurdity of determining a volition by a volition, overlooked that, according to our most common and necessary conceptions of cause, the first movement or action of cause must be determined by the cause itself, and that to deny this, is in fact to deny cause. If cause have not within itself a _nisus_ to produce phenomena, then wherein is it a cause? He overlooked, too, that in assigning as the cause or motive of volition, the state of the will, he really gave the will a self-determining power, and granted the very point he laboured to overthrow. The point in dispute, therefore, between us and Edwards, is not, after all, the self-determining power of the will. If will be a cause, it will be self-determining; for all cause is self-determining, or, in other words, is in its inherent nature active, and the ground of phenomena. But the real point in dispute is this: "_Is the will necessarily determined, or not?_" The inherent nature of cause may be so constituted and fixed, that the _nisus_ by which it determines itself to produce phenomena, shall take place according to invariable and necessary laws. This we believe to be true with respect to all physical causes. Heat, electricity, galvanism, magnetism, gravitation, mechanical forces in general, and the powers at work in chemical of affinities, produce their phenomena according to fixed, and, with respect to the powers themselves, necessary laws. We do not conceive it possible for these powers to produce any other phenomena, under given circumstances, than those which they actually produce. When a burning coal is thrown into a mass of dry gunpowder, an explosion must take place. Now, is it true likewise that the cause which we call will, must, under given circumstances, necessarily produce such and such phenomena? Must its _nisus_, its self-determining energy, or its volition, follow a uniform and inevitable law? Edwards answers yes. Will is but the sensitivity, and the inherent nature of the will is fixed, so that its sense of the most agreeable, which is its most original _nisus_ or its volition, follows certain necessary laws,--necessary in relation to itself. If we know the state of any particular will, and its correlation to every variety of object, we may know, with the utmost certainty, what its volition will be at a given time, and under given circumstances. Moral necessity and physical necessity differ only in the terms,--not in the nature of the connexion between the terms. Volition is as necessary as any physical phenomenon.