We are all familiar with the quasi-personification of Desire, Reason, and Will, which in one form or another have governed the language of moral philosophy in all ages in which such philosophy has existed. Sometimes desire and reason have been represented as inviting the man in different directions, while the will has been supposed to decide which of the two directions shall be followed. Sometimes the opposition has been represented as lying rather between different desires, of which reason however (according to the superstition) supplies the object to the one, while some irrational appetite is the source of the other; the will being the arbiter which determines the action according to the rational or irrational desire. Meanwhile criticism has been always ready to suggest that the only possible conflict is between desires, to which reason is related only as the minister who counts the cost and calculates means, without having anything to do with their initiation or their direction to an end; that the only tenable distinction between irrational and rational desires is really one between desire for the nearer pleasure and desire for the more remote, or between desire for a pleasure which a just calculation would pronounce to be overbalanced by the pains incidental to or consequent upon its attainment, and desire for one not liable to be thus cancelled in the total result. (§ 116 ¶ 1)

When this view is accepted, the will is naturally taken to be merely a designation for any desire that happens for the time to be strong enough to determine action. No doubt, it will be said, there is a particular class of the phenomena observable by the inner sense—a class called acts of will—which are distinguished from other events that take place in nature as being directed by our feeling. But we are not entitled ot suppose that in the case of each man there is really a single agent or power exerted in his acts of willing, a single basis of these phenomena. To do so would be of a piece with the logical fiction of things underlying the several groups of phenomena which we connect by a common name. Any act of willing is the result of the manifold conditions which go to constitute the feeling by which it is directed—conditions most various in the various cases of willing. (§ 116 ¶ 2)

The same criticism may be applied to our usual assumptions in regard to desire, and intelligence or reason, which we are apt to distinguish from will, as faculties having something in common with it and yet different from it. No doubt, it may be said, there are certain inner acts or phenomena which in virtue of certain resemblances we describe by the common name desire; others which on a similar ground we designate perceptions, conceptions, and inferences, and afterwards reduce to the higher genus of intellectual acts. But we are deceived by a process of language if, having arrived at an abstract term to indicate the elements of likeness in these several groups of phenomena, we allow ourselves to believe in the existence of a single agent or faculty—desire as such—underlying the manifold desires of this or that man, and of another such faculty—intelligence or reason as such—underlying his manifold perceptions, conceptions, and inferences. (§ 116 ¶ 3)