4. But there are _exceptional cases_ where infantry may properly use only its fire; as-- (1.) When acting as a support to artillery, it should rarely, if ever, leave its position to use the bayonet; thereby endangering the safety of the guns which it is its first duty to guard. Its function, in this case, being purely defensive, it should act by its fire alone. (2.) Against a line of skirmishers deployed, a well-directed fire will usually be sufficiently effective. (3.) In mountain warfare, its only practicable mode of attack will sometimes be by its fire. 5. When both sides are _equally exposed_, the actual attack with the bayonet should not be preceded by a distant musketry fire; for, as in that case, our loss will generally be equal to the enemy's, this fire will give us no superiority in the charge, and the loss we have sustained will be therefore entirely thrown away. 6. Nevertheless, our actual attack should be _prepared_, when possible, by the infliction of such a loss on the enemy as will make him inferior to us at the decisive moment. In war, the object is not to test the comparative courage of the combatants, but to beat the enemy. We must never, therefore, when it can be avoided, fight him on equal terms; and so, never close with him without such a superiority in numbers, position, or spirit, as will make the chances decidedly in our favor. If, without exposing ourselves to much loss, we can inflict a considerable loss upon him, we shall render him inferior to us, both by the number of his men we have disabled, and by the demoralization thereby caused in his ranks. 7. This preparatory loss can be most effectually inflicted by the _fire of artillery_; as, from its great superiority of range, it can suffer but little, meanwhile, from the enemy's infantry fire. Our attacking infantry are thus enabled to keep out of the range of the fire of the infantry they are to attack, till the moment of advancing to close. 8. When we have no artillery disposable for the purpose, the preparatory effect may be produced by a _well-sustained fire of infantry_, provided it can find a sheltered position to deliver it from; or, by the fire of a heavy line of skirmishers. 9. If we can make the infantry we wish to attack _engage in a prolonged fire_, this will exhaust them, and thus render them inferior to us in strength and in spirit, even if we inflict on them but little loss. But as our attacking infantry should, in the mean time, be kept fresh, the preparatory fire, in such case, should not devolve on the troops that are to close with the enemy.