This study begins with an analysis of a charter from 958 – which leaves no doubt about the feudal character of Genoese social organization – and concludes with a graph theoretic bipartition of the fifteenth-century insurance network, one that identifies an oligarchic mercantile core of closely related mercantile families who may be considered to be in some way separate from the rest of the population. During the long period covered by the study (roughly the same amount of time as that which separates Christopher Columbus's discovery of America from the moon landing), western Europe underwent profound changes in its social organization and in the structure of economic exchange. These changes included the rise of the money economy and the use of nonland assets to generate capital in order to further extend business activities, both of which are now emblematic of the modern world.

This transformation is the central topic of the texts upon which the social sciences are founded. For Marx, it marks the rise of the objectification of social relationships; for Durkheim, the emergence of the division of labor and a shift in the structure of social solidarity; and for Weber, the birth of the mean rational culture. Researchers have devoted entire careers to commenting upon and contrasting the texts produced by these authors, and it is not my aim in this book to pile more work upon that existing body, nor do I wish to pass judgment upon these three great thinkers.