ABSTRACT
This chapter discusses how evolutionary change proceeds through the actions of clusters of individuals, the members of a small primitive village or the cabinet of a great nation. Each such cluster is characterized by a discernible relationship to a particular cultural potential and period and by a peculiar combination of abilities. The most distinctive characteristic of an evolutionary cluster is the presence in it of at least one irreplaceable individual, someone with such special gifts of imagination and thought that without him the cluster would assume an entirely different character. The chapter points out a characteristic of the sciences that deal with man's social behavior which is a great handicap in the human scientist's effort to capture the attention of the scientific and the responsible lay world. Inventions in the field of human behavior must draw directly and fully on existing forms of human behavior. Communication must initially be couched in a natural language.
