Since the knowledge that pertains to genius, or the knowledge of Ideas, is that knowledge which does not follow the principle of sufficient reason, so, on the other hand, the knowledge which does follow that principle is that which gives us prudence and rationality in life, and which creates the sciences. Thus men of genius are affected with the deficiencies entailed in the neglect of this latter kind of knowledge. Yet what I say in this regard is subject to the limitation that it only concerns them in so far as and while they are actually engaged in that kind of knowledge which is peculiar to genius; and this is by no means at every moment of their lives, for the great though spontaneous exertion which is demanded for the comprehension of Ideas free from will must necessarily relax, and there are long intervals during which men of genius are placed in very much the same position as ordinary mortals, both as regards advantages and deficiencies. On this account the action of genius has always been regarded as an inspiration, as indeed the name indicates, as the action of a superhuman being distinct from the individual himself, and which takes possession of him only periodically. The disinclination of men of genius to direct their attention to the content of the principle of sufficient reason will first show itself, with regard to the ground of being, as dislike of mathematics; for its procedure is based upon the most universal forms of the phenomenon space and time, which are themselves merely modes of the principle of sufficient reason, and is consequently precisely the opposite of that method of thought which seeks merely the content of the phenomenon, the Idea which expresses itself in it apart from all relations. The logical method of mathematics is also antagonistic to genius, for it does not satisfy but obstructs true insight, and presents merely a chain of conclusions in accordance with the principle of the ground of knowing. The mental faculty upon which it makes the greatest claim is memory, for it is necessary to recollect all the earlier propositions which are referred to. Experience has also proved that men of great artistic genius have no faculty for mathematics; no man was ever very distinguished for both. Alfieri relates that he was never able to understand the fourth proposition of Euclid. Goethe was constantly reproached with his want of mathematical knowledge by the ignorant opponents of his theory of colours. Here certainly, where it was not a question of calculation and measurement upon hypothetical data, but of direct knowledge by the understanding of causes and effects, this reproach was so utterly absurd and inappropriate, that by making it they have exposed their entire want of judgment, just as much as by the rest of their ridiculous arguments. The fact that up to the present day, nearly half a century after the appearance of Goethe’s theory of colours, even in