There is implicit in this rather ambiguous popular usage of the terms "social mind" and "social consciousness" a recognition of the dual aspect of society and of social groups. Society may be regarded at the same time from an individualistic and a collectivistic point of view. Looking at it from the point of view of the individual, we regard as social just that character of the individual which has been imparted to, and impressed upon, him as a result of his participation in the life of the group. Social psychology, from Baldwin's first studies of the development of personality in the child to Ellwood's studies of the society in its "psychological aspects" has been mainly concerned with the investigation of the effects upon the individual of his contacts with other individuals.[43] On the other hand, we have had, in the description of the crowd and the public by Le Bon, Tarde, Sighele, and their successors, the beginnings of a study of collective behavior and "corporate action." In these two points of view we seem to have again the contrast and the opposition, already referred to, between the nominalistic and realistic conceptions of society. Nominalism represented by social psychology emphasizes, or seems to emphasize, the independence of the individual. Realism, represented by collective psychology, emphasizes the control of the group over the individual, of the whole over the part. While it is true that society has this double aspect, the individual and the collective, it is the assumption of this volume that the touchstone of society, the thing that distinguishes a mere collection of individuals from a society is not like-mindedness, but corporate action. We may apply the term social to any group of individuals which is capable of consistent action, that is to say, action, consciously or unconsciously, directed to a common end. This existence of a common end is perhaps all that can be legitimately included in the conception "organic" as applied to society. From this point of view social control is the central fact and the central problem of society. Just as psychology may be regarded as an account of the manner in which the individual organism, as a whole, exercises control over its parts or rather of the manner in which the parts co-operate together to carry on the corporate existence of the whole, so sociology, speaking strictly, is a point of view and a method for investigating the processes by which individuals are inducted into and induced to co-operate in some sort of permanent corporate existence which we call society.