The chief points developed in this thesis are closely allied to each other in thought. Through the whole there runs a stream of ideas dealing with the nature of the social classes, the mechanisms of their formation and perpetuation, and the extent of and types of social class rigidity and mobility. The general theme is based on the theory that the barriers to social ascent and descent are in normal times more effective, as social institutions, than are the channels of mobility.

The chief points developed are:
The social classes are composed of social cliques or associative groups of families that consider themselves equal in status. Social transmission early puts the social class stamp upon all persons and this largely conditions their occupational choices and opportunity chances.

Castes are not social status groups; they are forms of social organization, largely peculiar to India, which function in civilization much as tribes do among primitives. They are clannish rather than cliquish. Nor are races or parts of races, as such, castes.

A survey of human history reveals that social status hierarchies are characteristic of almost all societies and that most people have lived in the social class into which they were born.

The mechanisms by which classes maintain their prestige are both ingenious and multifarious. When one mechanism gives way under the pressure of the times, others are found to accomplish a similar result.

The reforms of Greece, especially the democratic practice of voting public bonuses, did not lead to social equality or to opportunity for the lower classes.

The political reforms of Rome were significant only to the aristocratic and prosperous plebeians. As for the remainder of the plebs, nothing was done to improve their lot from the inception of Rome to the division of the Empire. At no time did mere wealth "corrupt" the aristocratic spirit of Rome, even in the hour of greatest despair for the old aristocratic families.

The decrees of Diocletian and his successors were devised as a means of maintaining production, of obtaining social security, and of repairing the imperial budget. They froze the social class structure as a means of preventing the disintegration of economic and social life.

The social class pyramid of Gallo-Rome and of early France was not determined by conquest, as stated in the familiar theory of Gumplowicz, Oppenheimer, Sorokin, etc. It was determined by the mechanisms of social class continuity and social class rigidity.. The same holds true in England after the first repercussions of the Norman Conquest had passed.

The feudal system allowed the better peasants to rise into the yeoman class. The early masters soon monopolized the crafts for their own class, and the early merchants laid the foundations of a commercial aristocracy and of later capitalism. The latter grew sufficiently powerful in some countries to displace the craftsmen, to disorganize agricultural life, and to create industrial slums.

When the feudal structure fell, the families which had formed its leadership did not "crash" in the same proportion as did the system; nor did the workers rise to greater dignity during that period.

The American Dream has nine lives. It was a part of Penn's propaganda; it was immortalized in the slogan: "Go West, young man." It has been incorporated into many textbooks and was a part of the last presidential campaign. It is a fiction stronger than truth.

Colonial society was conceived in an atmosphere of stratification and it became increasingly more hierarchical. The towns established in most western states were soon duplicates of towns on the seaboard. The frontier was settled by classes. The War Between the States destroyed the plantation economy, but it did not uproot a great proportion of the planter families.

Social stratification is indicated, if not confirmed, by most of the statistical studies made of occupational and social shifting.

The genealogical data unearthed by Galton and others confirm the theory of social class rigidity.

The idea of social mobility should be attributed largely to middle class ideology and experience. The "old middle class" is characterized by its competitive spirit, its family-career planning, its habits, its initiative. It has always been a barrier between the proletariat and greater opportunity.

The social class structures of all the great powers are showing signs of disintegration. The modern world is characterized by total war [1941], a condition which ultimately calls for the abolition of standards of exclusiveness, canons of respectability and reputability. Whether or not modern civilization can recruit its social and political leadership from schools and party organizations instead of from the families of the middle and upper social classes is one of the greatest puzzles of modern social theory.

The consensus of opinion seems to be that the social classes belong to society and are indispensable to a smooth, functional social system.