individual in his life as a member of an organised group is neither the sum of his fellow members as individuals, nor is it something that has other than a mental existence. It is the organised group as such, which exists only or chiefly in the persons of those composing it, but which does not exist in the mind of any one of them, and which operates upon each so powerfully just because it is something indefinitely greater, more powerful, more comprehensive than the mere sum of those individuals. Maciver feels that “it is important to clear out of the way this misleading doctrine of super-individual minds corresponding to social or communal organisations and activities,” and therefore goes on to say that “there is no more a great ‘collective’ mind beyond the individual minds in society than there is a great ‘collective’ tree beyond all the individual trees in nature. A collection of trees is a wood, and that we can study as a unity; so an aggregation of men is a society, a much more determinate unity; but a collection of trees is not a collective tree, and neither is a collection of persons or minds a collective person or mind. We can speak of qualities of tree in abstraction from any particular tree, and we can speak of qualities of mind as such, or of some particular kind of mind in relation to some type of situation. Yet in so doing we are simply considering the characteristic of like elements of individual minds, as we might consider the characteristic or like elements discoverable in individual trees and kinds of trees. To conceive because of these identities, a ‘collective’ mind as existing _beside_ those of individuals or a collective tree beside the variant examples is to run against the wall of the Idea theory.” Now, I am not proposing to commit myself to this last-named theory. It is not because minds have much in common with one another that I speak of the collective mind, but because the group as such is more than the sum of the individuals, has its own life proceeding according to laws of group life, which are not the laws of individual life, and because its peculiar group life reacts upon and profoundly modifies the lives of the individuals. I would not call a forest a collective tree; but I would maintain that in certain respects a forest, a wood, or a copse, has in a rudimentary way a collective life. Thus the forest remains the same forest though, after a hundred or a thousand years, all its constituent trees may be different individuals; and again the forest as a whole may and does modify the life of each tree, as by attracting moisture, protecting from violent and cold winds, harbouring various plants and animals which affect the trees, and so on.