It consists of a failure to perceive that military activity is, in many respects, a thing altogether apart, and depends on psychological and physiological conditions which have no analogies in the domain of ordinary economic effort.
That such must necessarily be the case can be very easily seen by following out the train of reasoning suggested by Mr.Frederic Harrison.
Mr.Harrison correctly assumes that no man, in ordinary life, will run the risk of being killed or mutilated except for the sake of some object the achievement of which is profoundly desired by him.

If a man, for instance, puts his hand into the fire in order to pick out something that has dropped among the burning coals, we naturally assume that this something is of the utmost value and importance to him.

We measure the value which a man places on the object by the desperate character of the means which he will take to gain it; and Mr.Harrison jumps to the conclusion that what holds good in ordinary life will hold equally good on the field of battle also.

Hence he argues--for this is his special point--that the willingness of the soldier to die fighting on behalf of his country shows how individuals of no unusual kind value their country's welfare more than their own lives, and how readily, such being the case, devotion to a particular country may be enlarged into a religious devotion to Humanity taken as a whole.

Now, there are occasions, no doubt, in which, a country being in desperate straits, the soldier's valour is heightened by devotion to the cause he fights for; but that ideal devotion like this affords no sufficient explanation of the peculiar character of military activity generally; and that there must be some deeper and more general cause at the back of it, is shown by the fact that some of the most reckless soldiers known to us have been mercenaries who would fight as willingly for one country as for another.