As regards intellectual work it remains a fact, indeed, that great decisions in the realm of thought and momentous discoveries and solutions of problems are only possible to an individual, working in solitude. But even the group mind is capable of genius in intellectual creation, as is shown above all by language itself, as well as by folk-song, folk-lore and the like. It remains an open question, moreover, how much the individual thinker or writer owes to the stimulation of the group in which he lives, or whether he does more than perfect a mental work in which the others have had a simultaneous share. In face of these completely contradictory accounts, it looks as though the work of Group Psychology were bound to come to an ineffectual end. But it is easy to find a more hopeful escape from the dilemma. A number of very different formations have probably been merged under the term 'group' and may require to be distinguished. The assertions of Sighele, Le Bon and the rest relate to groups of a short-lived character, which some passing interest has hastily agglomerated out of various sorts of individuals. The characteristics of revolutionary groups, and especially those of the great French Revolution, have unmistakably influenced their descriptions. The opposite opinions owe their origin to the consideration of those stable groups or associations in which mankind pass their lives, and which are embodied in the institutions of society. Groups of the first kind stand in the same sort of relation to those of the second as a high but choppy sea to a ground swell. McDougall, in his book on _The Group Mind_,[19] starts out from the same contradiction that has just been mentioned, and finds a solution for it in the factor of organisation. In the simplest case, he says, the 'group' possesses no organisation at all or one scarcely deserving the name. He describes a group of this kind as a 'crowd'. But he admits that a crowd of human beings can hardly come together without possessing at all events the rudiments of an organisation, and that precisely in these simple groups many of the fundamental facts of Collective Psychology can be observed with special ease (p. 22). Before the members of a random crowd of people can constitute something in the nature of a group in the psychological sense of the word, a condition has to be fulfilled; these individuals must have something in common with one another, a common interest in an object, a similar emotional bias in some situation or other, and ('consequently', I should like to interpolate) 'some degree of reciprocal influence' (p. 23). The higher the degree of 'this mental homogeneity', the more readily do the individuals form a psychological group, and the more striking are the manifestations of a group mind.