The subjects which in one respect belong to the fighting itself are MARCHES, CAMPS, and CANTONMENTS, for they suppose so many different situations of troops, and where troops are supposed there the idea of the combat must always be present.
The other subjects, which only belong to the maintenance, are SUBSISTENCE, CARE OF THE SICK, the SUPPLY AND REPAIR OF ARMS AND EQUIPMENT.
Marches are quite identical with the use of the troops.

The act of marching in the combat, generally called manoeuvring, certainly does not necessarily include the use of weapons, but it is so completely and necessarily combined with it that it forms an integral part of that which we call a combat.

But the march outside the combat is nothing but the execution of a strategic measure.

By the strategic plan is settled WHEN, WHERE, and WITH WHAT FORCES a battle is to be delivered--and to carry that into execution the march is the only means.
The march outside of the combat is therefore an instrument of strategy, but not on that account exclusively a subject of strategy, for as the armed force which executes it may be involved in a possible combat at any moment, therefore its execution stands also under tactical as well as strategic rules.

If we prescribe to a column its route on a particular side of a river or of a branch of a mountain, then that is a strategic measure, for it contains the intention of fighting on that particular side of the hill or river in preference to the other, in case a combat should be necessary during the march.
But if a column, instead of following the road through a valley, marches along the parallel ridge of heights, or for the convenience of marching divides itself into several columns, then these are tactical arrangements, for they relate to the manner in which we shall use the troops in the anticipated combat.
The particular order of march is in constant relation with readiness for combat, is therefore tactical in its nature, for it is nothing more than the first or preliminary disposition for the battle which may possibly take place.
As the march is the instrument by which strategy apportions its active elements, the combats, but these last often only appear by their results and not in the details of their real course, it could not fail to happen that in theory the instrument has often been substituted for the efficient principle.