This chapter discusses the constraints of social systems on individuals and their internal worlds, and the effects that unconscious fantasies, actions, thoughts and feelings have on social systems. The effects of social facts and forces are as likely to be unconscious as conscious. The concept of the social unconscious differs from the traditional Jungian concept of the collective unconscious, with its emphasis on the inheritance of acquired characteristics. In various kinds of social systems, people tend unconsciously to recreate situations that have occurred at another time and space, such that the new or later situation may be taken as ‘equivalent’ to the old or previous one. In group analysis and in all forms of group psychotherapy it is necessary to keep in mind the welfare and development of each individual member of the Group. An essential feature of increased ‘psychic muscle’ is the ability to withstand and even to make creative use of social resistance to ‘revolutionary’ action.