Americans have never been other than ambivalent in their commitment to cultural variety, as against their longing for cultural uniformity. Today, this ambivalence is becoming a central concern of public policy. For, as urban planning becomes an increasingly visible and legitimate part of the activity of the public sector, its power will grow to support or to undermine cultural diversity in the traditional seat of that diversity– the cities.  Like the myth of a homogeneous “suburbia,” which for a long time obscured, and to some extent still obscures, the actual variety of suburban life, complacence about the cultural diversity of cities may blind us to the conditions which sustain it. My aim in this essay is to take what I and others have learned about the variety of suburban styles of life, and to relate this knowledge, first to some of the more pervasive pluralisms of American culture, and then to a few of the problems of planning for urban diversity.