It is in discussion that Professor Ross sees one of the main hopes of progress.[XXIII-28] Discussion brings conflicts to a head, and leads to group progress. Discussion changes a person’s opinions. Adequate discussion leads to the settlement of a conflict and the creation of an established public opinion, which remains in force until a new invention occurs, a resultant conflict ensues, and a new public opinion comes into power. In 1920, Professor Ross made his largest and most important contribution to social thought in his _Principles of Sociology_. This work, however, is essentially a treatise in social psychology. The original social forces are the human instincts, notably the fighting instinct, the gregarious instinct, the parental instinct, the curiosity instinct. The derivative social forces are societal complexes which tend to satisfy instinctive cravings. Professor Ross’ classification of the derivative social forces, or interests, is primarily fourfold. These fundamental interests are wealth, government, religion, and knowledge. This classification contains only two, or at best three, of the six groups of interests which are found in Professor Small’s exhibit.[XXIII-29] Professor Ross’ analysis of the process of socialization has been indicated in Chapter XXI. This phenomena is to be sharply distinguished from ossification, which is the hardening of social life into rigid forms.[XXIII-30] Groups often become unduly solidified. The salvation of such a situation lies in individuation, which is a process of pulverizing social lumps and releasing the action of their members.[XXIII-31] Any movement that develops that spirit of personal liberty leads to individuation. “Commercialization is the increasing subjection of any calling or function to the profits motive.”[XXIII-32] The various factors which hold the profits motive in check are: (1) pleasure in creative activity; (2) pride in the perfection of one’s product; (3) the desire to live up to accepted standards of excellence; (4) abhorrence of sham in one’s work; (5) interest in the welfare of the customer; (6) the social service motive. The profits motive, however, receives support from many social tendencies, notably: (1) the increasing distance between producer and consumer; (2) the growing differentiation between principals and subordinates; (3) the increasing importance of capital in the practice of an art or occupation. Professor Ross has set forth a valuable exhibit of the canons of social reconstruction.[XXIII-33] (1) Reforms must not do violence to human nature. (2) They must square with essential realities. (3) They should be preceded by a close sociological study of the situation which it is planned to change. (4) Reforms should be tried out on a small scale before being adopted on a large scale. (5) A reform should be the outcome of a social movement. (6) Under a popular government, reforms should move according to legal and constitutional methods.