This division into tactics and strategy is now in almost general use, and every one knows tolerably well under which head to place any single fact, without knowing very distinctly the grounds on which the classification is founded.  But when such divisions are blindly adhered to in practice, they must have some deep root.  We have searched for this root, and we might say that it is just the usage of the majority which has brought us to it.  On the other hand, we look upon the arbitrary, unnatural definitions of these conceptions sought to be established by some writers as not in accordance with the general usage of the terms.

According to our classification, therefore, tactics is the theory of the use of military forces in combat.  Strategy is the theory of the use of combats for the object of the war.

The way in which the conception of a single, or independent combat, is more closely determined, the conditions to which this unit is attached, we shall only be able to explain clearly when we consider the combat; we must content ourselves for the present with saying that in relation to space, therefore in combats taking place at the same time, the unit reaches just as far as personal command reaches; but in regard to time, and therefore in relation to combats which follow each other in close succession, it reaches to the moment when the crisis which takes place in every combat is entirely passed.

That doubtful cases may occur, cases, for instance, in which several combats may perhaps be regarded also as a single one, will not overthrow the ground of distinction we have adopted, for the same is the case with all grounds of distinction of real things which are differentiated by a gradually diminishing scale.  There may, therefore, certainly be acts of activity in War which, without any alteration in the point of view, may just as well be counted strategic as tactical; for example, very extended positions resembling a chain of posts, the preparations for the passage of a river at several points, &c.

Our classification reaches and covers only the use of the military force.  But now there are in War a number of activities which are subservient to it, and still are quite different from it; sometimes closely allied, sometimes less near in their affinity.  All these activities relate to the maintenance of the military force.  In the same way as its creation and training precede its use, so its maintenance is always a necessary condition.  But, strictly viewed, all activities thus connected with it are always to be regarded only as preparations for fighting; they are certainly nothing more than activities which are very close to the action, so that they run through the hostile