The relations of an individual to his parents and to his brothers and sisters, to the object of his love, and to his physician--in fact all the relations which have hitherto been the chief subject of psycho-analytic research--may claim to be considered as social phenomena; and in this respect they may be contrasted with certain other processes, described by us as 'narcissistic', in which the satisfaction of the instincts is partially or totally withdrawn from the influence of other people. The contrast between social and narcissistic--Bleuler would perhaps call them 'autistic'--mental acts therefore falls wholly within the domain of Individual Psychology, and is not well calculated to differentiate it from a Social or Group Psychology. The individual in the relations which have already been mentioned--to his parents and to his brothers and sisters, to the person he is in love with, to his friend, and to his physician--comes under the influence of only a single person, or of a very small number of persons, each one of whom has become enormously important to him. Now in speaking of Social or Group Psychology it has become usual to leave these relations on one side and to isolate as the subject of inquiry the influencing of an individual by a large number of people simultaneously, people with whom he is connected by something, though otherwise they may in many respects be strangers to him. Group Psychology is therefore concerned with the individual man as a member of a race, of a nation, of a caste, of a profession, of an institution, or as a component part of a crowd of people who have been organised into a group at some particular time for some definite purpose. When once natural continuity has been severed in this way, it is easy to regard the phenomena that appear under these special conditions as being expressions of a special instinct that is not further reducible, the social instinct ('herd instinct', 'group mind'), which does not come to light in any other situations. But we may perhaps venture to object that it seems difficult to attribute to the factor of number a significance so great as to make it capable by itself or arousing in our mental life a new instinct that is otherwise not brought into play. Our expectation is therefore directed towards two other possibilities: that the social instinct may not be a primitive one and insusceptible of dissection, and that it may be possible to discover the beginnings of its development in a narrower circle, such as that of the family.