§ 53. The last part of our work presents itself as the most serious, for it relates to the action of men, the matter which concerns every one directly and can be foreign or indifferent to none. It is indeed so characteristic of the nature of man to relate everything else to action, that in every systematic investigation he will always treat the part that has to do with action as the result or outcome of the whole work, so far, at least, as it interests him, and will therefore give his most serious attention to this part, even if to no other. In this respect the following part of our work would, in ordinary language, be called practical philosophy, in opposition to the theoretical, which has occupied us hitherto. But, in my opinion, all philosophy is theoretical, because it is essential to it that it should retain a purely contemplative attitude, and should investigate, not prescribe. To become, on the contrary, practical, to guide conduct, to transform character, are old claims, which with fuller insight it ought finally to give up. For here, where the worth or worthlessness of an existence, where salvation or damnation are in question, the dead conceptions of philosophy do not decide the matter, but the inmost nature of man himself, the Dæmon that guides him and that has not chosen him, but been chosen by him, as Plato would say; his intelligible character, as Kant expresses himself. Virtue cannot be taught any more than genius; indeed, for it the concept is just as unfruitful as it is in art, and in both cases can only be used as an instrument. It would, therefore, be just as absurd to expect that our moral systems and ethics will produce virtuous, noble, and holy men, as that our æsthetics will produce poets, painters, and musicians. Philosophy can never do more than interpret and explain what is given. It can only bring to distinct abstract knowledge of the reason the nature of the world which in the concrete, that is, as feeling, expresses itself comprehensibly to every one. This, however, it does in every possible reference and from every point of view. Now, as this attempt has been made from other points of view in the three preceding books with the generality that is proper to philosophy, in this book the action of men will be considered in the same way; and this side of the world might, indeed, be considered the most important of all, not only subjectively, as I remarked above, but also objectively. In considering it I shall faithfully adhere to the method I have hitherto followed, and shall support myself by presupposing all that has already been advanced. There is, indeed, just one thought which forms the content of this whole work. I have endeavoured to work it out in all other spheres, and I shall now do so with regard to human action. I shall then have done all that is in my power to communicate it as fully as possible.