The same considerations afford an explanation of a peculiarity of Russian armies which has often been noted in previous wars, and which was very conspicuous in the late wars; namely, their weakness in attack and their great strength when on the defensive. For, in attacking, a Russian army is in the main merely obeying the will of the commander-in-chief in virtue of custom, habit, and a form of strong collective suggestion; but in retreat and on the defensive, each man’s action becomes truly volitional, all are animated by a common purpose, and all will the same end, the safety of the whole with which that of each member is bound up. The psychology of a patriot army is peculiarly simplified, as compared with that of most other large human groups, by two conditions; on the one hand, the restriction of the intellectual processes, by which the large means for the pursuit of the common end are chosen, to one or a few minds only; on the other hand, the definiteness and singleness of its purpose and the presence of this clear and strong purpose in the minds of all. Other groups that enjoy in some degree the latter condition of simplicity of collective mental life are associations voluntarily formed and organised for the attainment of some single well-defined end. In them the former condition is generally completely lacking and the deliberative processes, by which their means are chosen, are apt to be very complex and ineffective, owing to lack of customary organisation. Such associations illustrate more clearly than any other groups the part played by the idea of the whole in the minds of the individuals in constituting and maintaining the whole. A desire or purpose being present in many minds, the idea of the association arises in some one or more of them, and, being communicated to others, becomes the immediate instrument through which the association is called into being; and only so long as this idea of the whole as an instrument for attaining the common end persists in the minds of the individuals does the association continue to exist. In this respect such an association is at the opposite end of the scale from the fortuitous crowd, which owes its existence to the accidents of time and place merely. Human groups of other kinds owe their existence in various proportions to these two conditions; such groups, for example, as are constituted by the members of a church, of a university or a school, of a profession or a township. Others, such as nations, owe their inception to the accidents of time and place, to physical boundaries and climatic conditions; and, in the course of their evolution, become more and more dependent for their existence on the idea of the whole and the sentiment organised about it in the minds of their members; and they may, like the Jewish people, arrive in the course of time at complete dependence on the latter condition.