Will it be said that the judgments founded on the concept of _the good_ are insignificant and worthless because neither man nor the good of man can be the measure of things? If this remark is useful for abating human pride and preventing childish illusions, it does not efface the primordial distinction between good and evil inherent to the human mind, nor would one wish to deduce from it the vanity of all morality, and the equal worth of all the manifestations of life. The proof, moreover, that the rule of _the good_ is above man is that it judges and condemns him pitilessly; it is that consciousness, independently of the painful or agreeable sensations that it receives from things, establishes between them a fitness (_convenance_), a hierarchy, and constitutes the harmonious unity of the universe itself in the supreme idea of the sovereign good. If the legitimacy of the confidence which the conscience has in its rule is to be contested, I do not see why we should not contest that of the confidence of pure thought in itself. Then everything crumbles to pieces, both science and conscience, in the same abyss. In reality, the good, the beautiful, the relations of fitness and of harmony, are so many principles of knowledge, which progress, like physical knowledge, by the culture of the mind. The form of the moral judgments is universal, and identical in every man; it is this form alone which constitutes man as a moral being; but the contents of this form vary unceasingly in history, according to times and places. Everywhere and always man has sought the good, but he has not always placed it in the same things; he has formed different ideas of it, and these ideas have become more and more noble and pure in proportion as his life itself has been ennobled and purified. That is why there is a history of morality, of religion, of aesthetics, as there is a history of the natural sciences, although progress in these two classes has been of an opposite nature and accomplished according to different laws. However this may be, we may conclude that if mathematics, by the concept of number, the abstract form of sensation, is the mould and framework of the sciences of Nature, ethics, by _the categorical imperative_, the abstract form of the activity of spirit, is the foundation of the moral sciences, which are as diverse as the various activities of the ego, each having special rules and criteria, no doubt, but always falling under the common form of obligation.