We must not leave the Kantian theory with the impression that it is simply the caprice of a philosopher's brain. In two respects, at least, it presents us, as we shall see, with elements that must be adopted; and even where false it is highly instructive. Kant's fundamental error is in his conception that all desires or inclinations are for private pleasure, and are, therefore, to be excluded from the conception of the moral end. Kant's conclusion, accordingly, that the good will is purely formal follows inevitably if ever it is granted that there is any intrinsic opposition between inclination as such, and reason or moral law as such. If there is such an opposition, _all_ desire must be excluded from relation to the end. We cannot make a compromise by distinguishing between higher and lower desires. On the contrary, if the end is to have content, it must include all desires, leaving out none as in itself base or unworthy. Kant's great negative service was showing that the ascetic principle logically results in pure formalism--meaning by ascetic principle that which disconnects inclinations from moral action. Kant's positive service was, first, his clear insight into the fact that the good is to be found only in activity; that the will itself, and nothing beyond itself, is the end; and that to adopt any other doctrine, is to adopt an immoral principle, since it is to subordinate the will (character, self and personality), to some outside end. His second great service was in showing the necessity of putting in abeyance the immediate satisfaction of each desire as it happens to arise, and of subordinating it to some law not to be found in the particular desire. He showed that not the particular desire, but only the desire as controlled by the idea of law could be the motive of moral action. And if he fell into the error of holding that this meant that the desire must be excluded from the moral motive, this error does not make it less true that every particular desire must be controlled by a universal law. The truth of asceticism is that the desire must be checked until subordinated to the activity of the whole man. See Caird, Op. cit., Vol. II, p. 200; pp. 203-207; 226-227. XXXII. The Problem and Its Solution.