Between the fourteenth and sixteenth centuries, Japanese society underwent fundamental changes that led to the dissolution of the traditional state structure and the appearance of new forms of state and social organization. This chapter focuses on the period from the middle of the sixteenth century to the end of the seventeenth century. It begins with the final stages of the era of social upheaval and ends a century after the formation of a unified political regime. During these 150 years a new state structure became firmly established, and the stable social environment that evolved led to a relatively steady improvement in the lives of the people. The factors that brought about this social change and the precise nature of its impact on the structure of society and the lives of the people are issues about which the opinions of researchers continue to differ. In this chapter, I would like to touch first on one social phenomenon that is central to the development of religion and thought in this period but has not received from researchers the attention it deserves. I refer to the establishment of the ie (house or lineage) as the basic unit of social organization among both the bushi (warrior class) and the rest of the population.

What I refer to here as the “house” is centered on the family. But the house was not identical with a consanguineous family unit; it incorporated as members unrelated persons such as employees (hōkōnin), and it was possible for an adopted heir who had no blood relationship to the other members to succeed to its headship.