The three groups which Professor Cooley has called primary are so labeled because through them the individual gets “his earliest and completest experience of social unity.”[XXIII-7] The family, play groups, and neighborhoods remain throughout life as the experience bases from which the more complex phases of life receive their interpretation. An unbounded faith in human nature is enjoyed by Professor Cooley. Human nature comprises those sentiments and impulses which are distinctly superior to those of the higher animals, such as sympathy, love, resentment, ambition, the feeling of right and wrong.[XXIII-8] The improvement of society, according to Professor Cooley, does not involve any essential change in human nature but rather “a larger and higher application of its familiar impulses.”[XXIII-9] Communication is a fundamental concept in Professor Cooley’s system of social thought. Communication is “the mechanism through which human relations exist and develop.”[XXIII-10] Professor Cooley has pointed out that not only does language constitute the symbols of the mind, but that in a sense all objects and actions are mental symbols. Communication is the means whereby the mind develops a true human nature. The symbols of our social environment “supply the stimulus and framework for all our growth.” Thus the communication concept furnishes a substantial basis for understanding the psycho-sociologic phenomena which are ordinarily called suggestion and imitation. Personality has its origin partly in heredity and partly “in the stream of communication, both of which flow from the corporate life of the race.” A study of communication shows that the individual mind is not a separate growth, but an integral development of the general mind. The means of communication developed remarkably in the nineteenth century, chiefly in the following ways: (1) in expressiveness, that is, in the range of ideas and feelings they are competent to carry; (2) in the permanence in recording; (3) in swiftness of communication; and (4) in diffusion to all classes of people.[XXIII-12] Thus society can be organized on the bases of intelligence and of rationalized and systematized feelings rather than on authority, autocracy, and caste. A free intercourse of ideas, that is, free and unimpeded communication, will not produce uniformity. Self feeling will find enlarged opportunities for expression. An increased degree of communication furnishes the bases for making the individual conscious of the unique part he can and should play in improving the quality of the social whole. On the other hand, freedom of communication is tending to produce “the disease of the century,” namely, the disease of excess, of overwork, of prolonged worry, of a competitive race for which men are not fully equipped.[XXIII-13]