They differ only in the mode of developing the necessary determination of will. According to Locke, desire is in itself a necessary modification of our being produced in its correlation with objects; and volition is a necessary consequent of desire when excited at any given moment to a degree which gives the most intense sense of uneasiness at that moment. "The greatest present uneasiness is the spur of action that is constantly felt, and for the most part, determines the will in its choice of the next action." (book 2. ch. 21, § 40.) According to Edwards, desire is not distinguishable from will as a faculty, and the strongest desire, at any moment, is the volition of that moment. Edwards's analysis is more nice than Locke's, and his whole developement more true to the great principle of the system--necessary determination. Locke, in distinguishing the will from the desire, seems about to launch into a different psychology, and one destructive of the principle. II. THE LEGITIMATE CONSEQUENCES OF EDWARDS'S SYSTEM. These consequences must, I am aware, be deduced with the greatest care and clearness. The deduction must be influenced by no passion or prejudice. It must be purely and severely logical--and such I shall endeavour to make it. I shall begin with a deduction which Edwards has himself made. I. There is no self-determining power of will, and of course no liberty consisting in a self-determining power. A self-determining power of will is a supposed power, which will has to determine its own volitions. Will is the faculty of choice, or the capacity of desire, emotion, or passion. Volition is the strongest desire, or the sense of the most agreeable at any given moment. Volition arises from the state of the mind, or of the will, or sensitivity itself, in correlation with the nature and circumstances of the object. Now, if the will determined itself, it would determine its own state, in relation to objects. But to determine is to act, and therefore, for the will to determine is for the will to act; and for the will to determine itself, is for the will to determine itself by an act. But an act of the will is a volition; therefore for the will to determine itself is to create a volition by a volition. But then we have to account for this antecedent volition, and it can be accounted for only in the same way. We shall then have an infinite, or more properly, an indefinite series of volitions, without any first volition; consequently we shall have no self-determiner after all, because we can arrive at no first determiner, and thus the idea of self-determination becomes self-destructive. Again, we shall have effects without a cause, for the series in the nature of the case never ends in a first, which is a cause per se. Volitions are thus contingent, using this word as a synonyme of chance, the negative of cause.