_Logistics_; 4th._Tactics_.Several general treatises on this art add another branch, called _The Policy of War_, or the relations of war with the affairs of state.
_Strategy_ is defined to be the art of directing masses on decisive points, or the hostile movements of armies beyond the range of each other's cannon.

_Engineering_ embraces all dispositions made to enable troops to resist a superior force the longest time possible; and also the means resorted to by the opposing army to overcome these material obstacles.

_Logistics_ embraces the practical details of moving and supplying armies.

_Tactics_ is the art of bringing troops into action, or of moving them in the presence of an enemy, that is, within his view, and within the reach of his artillery.

All these are most intimately connected.