Before attacking this problem directly, I must clear away several misconceptions of the “group mind,” which I cannot accept as a part of this theory. First, this thesis need not exclude the operation of physical and biological forces on social groups, any more than it excludes their operation on any individual, who is also a psychological unit. Society may well be a unit, just as the individual is, in a world of varying forces—climate, birth rates, and the like. Second, a theory of group mind may be empirical, and need not necessarily rest on an idealistic conception of the {Volksgeist}. By adopting the historical method, rather than the statistical, relying on values to indicate our problem rather than trying to express it in terms of natural science, we shall find ourselves treating the theory of the group in a realistic and empirical way, eschewing the dogmatism of applying a priori principles to human material, and the equal fallacy of considering minds in the same terms as chemical elements.[8] Third, a modern social psychology need not be a literal transcription of Durkheim or Wundt, relying on an antiquated psychology for its analogies and its basic conceptions. A theory of group mind today must recognize that personality is not always a unity, that it is never a complete unity; the vast field of the unconscious in mental life has just been opened to view. Both of these conceptions apply to the mental life of men in great masses as truly as when alone. Neither the individual nor the group is something hard, fixed and static; neither can be summed up as a group of faculties or a system of ideas. Both individual and group must be conceived in process, to take the words of Lindemann,[9] as “the total equipment with which man responds to his environment, all that enters into behavior from the side of human nature.”