Because this simplicity of knowledge requisite in War was not attended to, but that knowledge was always jumbled up with the whole impedimenta of subordinate sciences and arts, therefore the palpable opposition to the events of real life which resulted could not be solved otherwise than by ascribing it all to genius, which requires no theory and for which no theory could be prescribed. 42. ON THIS ACCOUNT ALL USE OF KNOWLEDGE WAS DENIED, AND EVERYTHING ASCRIBED TO NATURAL TALENTS. People with whom common sense had the upper hand felt sensible of the immense distance remaining to be filled up between a genius of the highest order and a learned pedant; and they became in a manner free-thinkers, rejected all belief in theory, and affirmed the conduct of War to be a natural function of man, which he performs more or less well according as he has brought with him into the world more or less talent in that direction. It cannot be denied that these were nearer to the truth than those who placed a value on false knowledge: at the same time it may easily be seen that such a view is itself but an exaggeration. No activity of the human understanding is possible without a certain stock of ideas; but these are, for the greater part at least, not innate but acquired, and constitute his knowledge. The only question therefore is, of what kind should these ideas be; and we think we have answered it if we say that they should be directed on those things which man has directly to deal with in War. 43. THE KNOWLEDGE MUST BE MADE SUITABLE TO THE POSITION. Inside this field itself of military activity, the knowledge required must be different according to the station of the Commander. It will be directed on smaller and more circumscribed objects if he holds an inferior, upon greater and more comprehensive ones if he holds a higher situation. There are Field Marshals who would not have shone at the head of a cavalry regiment, and _vice versa_. 44. THE KNOWLEDGE IN WAR IS VERY SIMPLE, BUT NOT, AT THE SAME TIME, VERY EASY. But although the knowledge in War is simple, that is to say directed to so few subjects, and taking up those only in their final results, the art of execution is not, on that account, easy. Of the difficulties to which activity in War is subject generally, we have already spoken in the first book; we here omit those things which can only be overcome by courage, and maintain also that the activity of mind, is only simple, and easy in inferior stations, but increases in difficulty with increase of rank, and in the highest position, in that of Commander-in-Chief, is to be reckoned among the most difficult which there is for the human mind. 45. OF THE NATURE OF THIS KNOWLEDGE.