This is a study of Japan"s home-grown concept of seikatsusha that resembles "citizen," "people," "consumer," "common man," and "the public," though not exactly identical with any of them. The idea has occupied an important place in Japanese everyday life, academia, and progressive movements. This book presents an extensive genealogy of the concept of seikatsusha, from the beginning of the 20th century to the present day. While examining the philosophy of such thinkers as Kiyoshi Miki, Nobuyuki Onuma, and Shunsuke Tsurumi, the book scrutinizes the debate over seikatsusha, which has been undertaken by a variety of political and intellectual movements, including Shiso no kagaku (Science of thought), Beheiren (Citizens for Peace in Vietnam), and the Seikatsu Club. The book points to the viability of the idea of seikatsusha in a sustainable welfare society in the 21st century and is the first in English to fully investigate the concept within Japan"s historical and structural context.