If our opponent is to be made to comply with our will, we must place him in a situation which is more oppressive to him than the sacrifice which we demand; but the disadvantages of this position must naturally not be of a transitory nature, at least in appearance, otherwise the enemy, instead of yielding, will hold out, in the prospect of a change for the better. Every change in this position which is produced by a continuation of the War should therefore be a change for the worse. The worst condition in which a belligerent can be placed is that of being completely disarmed. If, therefore, the enemy is to be reduced to submission by an act of War, he must either be positively disarmed or placed in such a position that he is threatened with it. From this it follows that the disarming or overthrow of the enemy, whichever we call it, must always be the aim of Warfare. Now War is always the shock of two hostile bodies in collision, not the action of a living power upon an inanimate mass, because an absolute state of endurance would not be making War; therefore, what we have just said as to the aim of action in War applies to both parties. Here, then, is another case of reciprocal action. As long as the enemy is not defeated, he may defeat me; then I shall be no longer my own master; he will dictate the law to me as I did to him. This is the second reciprocal action, and leads to a second extreme (_second reciprocal action_). 5. UTMOST EXERTION OF POWERS. If we desire to defeat the enemy, we must proportion our efforts to his powers of resistance. This is expressed by the product of two factors which cannot be separated, namely, _the sum of available means_ and _the strength of the Will_. The sum of the available means may be estimated in a measure, as it depends (although not entirely) upon numbers; but the strength of volition is more difficult to determine, and can only be estimated to a certain extent by the strength of the motives. Granted we have obtained in this way an approximation to the strength of the power to be contended with, we can then take of our own means, and either increase them so as to obtain a preponderance, or, in case we have not the resources to effect this, then do our best by increasing our means as far as possible. But the adversary does the same; therefore, there is a new mutual enhancement, which, in pure conception, must create a fresh effort towards an extreme. This is the third case of reciprocal action, and a third extreme with which we meet (_third reciprocal action_). 6. MODIFICATION IN THE REALITY.