[23] It is frequently customary on the outbreak of a war to issue “Instructions for campaign,” in order to prepare troops, trained according to superannuated regulations, for action on a strange theater of war. It is desirable to disseminate the first experiences gained in action to all parts of the army. We failed to do this in 1870, and all organizations were therefore compelled to gain this experience for themselves. Even as late as the 18th of August, 1870, the Füsilier Battalion of the 85th Infantry advanced in double column formed on the center, although the campaign in Bohemia had already demonstrated that this formation was out of date. See MOLTKE, _Feldzug von 1859_, p. 65. Further development and justification of the principles of the drill regulations, and the modification of those principles under certain assumptions, are reserved to the science of tactics. Drill regulations should not be textbooks of tactics, but, on the other hand, a textbook of tactics should deal with formations only in so far as that is necessary to ensure a clear comprehension of the fundamental principles. “Regulations and the science of combat are in a certain sense very different subjects. The regulations are law, authority--no doubt can be entertained on this point; but that also invests them with the character of something fixed, at least for a certain space of time. They cannot be kept up to date so as to meet quickly enough the rapidly changing and ever growing demands of modern combat: that would indeed be an unfair requirement, impossible of realization. Here must enter the science of combat, which should be independent in every direction, which should know no fixed rules, and which should point to no other authority than that of truth and reality. It is not the province of the science of combat, like that of regulations, to retain that which is in keeping with prevailing views and forms; it must take into consideration the fleeting theory and practice, ever developing and changing anew.”[24] [24] KEIM, _Gegenwärtiger Stand der Gefechtslehre_, p. 1. A positive system of tactics will therefore be based upon one’s own drill regulations, from the standpoint of which it will investigate and compare the principles of the service manuals of the different powers, and finally develop the science still further by the aid of experience gained from military history and the knowledge of the effect of weapons. While these are the ever changing but nevertheless measurable factors of tactical reflection, a third, perhaps the most important factor, must be added, viz., that the leader must reckon with the action of men frequently exposed to the influence of great exertions and great mental agitation. _A doctrine of tactics which does not properly appreciate the psychological element stagnates in lifeless pedantry._ THE FORMAL TACTICS OF INFANTRY. I. ORGANIZATION AND EQUIPMENT. 1. THE IMPORTANCE AND EMPLOYMENT OF INFANTRY.