It is impossible to determine theoretically what losses troops are able to endure. After the Franco-German War it was believed that troops had reached the limit of endurance after losing one-third to one-fourth of their strength. Nowadays this limit would appear to be reached much sooner. It may be pointed out, however, that the neglect of continuing the attack at Colenso (loss 5.8%), and at Spionskop (loss 7.2%), may, in part, be charged to lack of energy in the commander; and that the Brigade of Highlanders, consisting of 2000 rifles and deployed on a front of about 4000 m., in the engagement at Paardeberg (loss 13.4%), lacked the necessary depth to continue the attack. The greater the degree of efficiency and freshness of troops, and the less the degree of suddenness with which they enter a difficult situation, the greater the losses which they will be capable of enduring. Furthermore, we should not forget that our modern personnel has become much more susceptible to the impressions of battle. The steadily improving standards of living tend to increase the instinct of self-preservation and to diminish the spirit of self-sacrifice. The spirit of the times looks upon war as an avoidable evil, and this militates directly against that courage which has a contempt for death. The fast manner of living at the present day undermines the nervous system,[186] the fanaticism and the religious and national enthusiasm of a bygone age are lacking, and, finally, the physical powers of the human species are also partly diminishing. The influence exerted by officers on the firing line is nowadays, however, considerably smaller than in the past, so much so that they can actually control only the nearest skirmishers. In addition, the nerve-racking impressions on the battlefield are much greater at present than in the past. The “_void of the battlefield_”[187] has become especially pronounced since the introduction of smokeless powder. “_The invisibility of the enemy directly affects the morale of the soldier, the sources of his energy and his courage. The soldier who cannot see his enemy, is inclined to see him everywhere. It is but a step from this impression to hesitancy and then to fear._ The inertia of the troops for whole days at Magersfontain, Colenso, and Paardeberg, frequently more than 800 m. from the enemy, was not produced by their losses, but by the moral depression which is caused within the effective zone of rifle fire.” (General NÉGRIER.)[188]