He begins his book by describing the change in social conditions taking place. He observed that over the previous seven hundred years the social and economic conditions of men had become more equal. The aristocracy, Tocqueville believed, was gradually disappearing as the modern world experienced the beneficial effects of equality. Tocqueville traced the development of equality to a number of factors, such as granting all men permission to enter the clergy, widespread economic opportunity resulting from the growth of trade and commerce, the royal sale of titles of nobility as a monarchical fundraising tool, and the abolition of primogeniture.
Tocqueville described this revolution as a "providential fact" of an "irresistible revolution," leading some to criticize the determinism found in the book. However, based on Tocqueville's correspondences with friends and colleagues, Marvin Zetterbaum, Professor Emeritus at University of California Davis, concludes that the Frenchman never accepted democracy as determined or inevitable. He did, however, consider equality more just and therefore found himself among its partisans.
Given the social state that was emerging, Tocqueville believed that a "new political science" would be needed, in order to:
[I]nstruct democracy, if possible to reanimate its beliefs, to purify its motives, to regulate its movements, to substitute little by little the science of affairs for its inexperience, and knowledge of its true instincts for its blind instincts; to adapt its government to time and place; to modify it according to circumstances and men: such is the first duty imposed on those who direct society in our day.
The remainder of the book can be interpreted as an attempt to accomplish this goal thereby giving advice to those people who would experience this change in social states.