fact. If we hear that the enemy underfeed their prisoners, we shall feel genuine indignation, even if we are ourselves large employers paying wages which compel underfeeding. The formula is: sympathy with compatriots in all that they suffer through the common enemy, but indifference to all that they suffer from other causes. This shows that, as we asserted, the friendly feelings arising during war are derivative from the hostile ones, and could not exist in the same form or with the same wide-spread intensity if hatred did not exist to stimulate them. Those who see in national co-operation during war an instinctive mechanism which could be applied to international co-operation during peace have failed to understand the nature of the mechanism which war brings into play, or the fact that without enmity there is no stimulus to set it in motion.
There is, it is true, in addition to sex and parenthood, a form of instinctive co-operation which involves no enemy, and looks at first sight very hopeful as a social incentive. I mean that kind of co-operation in work which, so far as human beings are concerned, one finds most developed among uncivilized peoples, and which is carried to its highest perfection by ants and bees. Rivers, in his book on Instinct and the Unconscious (page 94 ff.) describes how the Melanesians carry out collective work apparently without any need of previous arrangements, by the help of the gregarious instinct. I do not believe, however, that much use can be made of this mechanism by civilized communities. The instinct involved appears to be very much weakened by civilization, and is probably incompatible with even the average degree of intellectual development that exists where school education is common. Moreover, even when it exists most strongly, it is not such as to make complicated large organizations possible. It seems also that with the progress of intelligence the individual grows more self-contained, less receptive to immediate impressions from other personalities, which survive chiefly in fragmentary and sporadic forms such as hypnotism. The primitive instinct for collective work is certainly one to be borne in mind, but I do not think it has any very important contribution to make to the solution of industrial problems.
In order to stimulate friendly feeling and diminish hostile feeling, the things that seem most important are: physical well-being, instinctive satisfaction, and absence of obvious conflict between the interests of different individuals or groups. On the first two heads, we have already said enough in considering instinctive happiness.
