183 C.C. Huang and J.A. Tucker (eds.), Dao Companion to Japanese Confucian Philosophy, Dao Companions to Chinese Philosophy 5, DOI 10.1007/978-90-481-2921-8_7, © Springer Science+Business Media Dordrecht 2014 7.1 Introduction This essay explores a philosophical moment, one involving the genealogy of some philosophical theories that developed between O GYŪ Sorai 荻生徂徠 (1666–1727) and K AIHO Seiryō 海保青陵 (1755–1817). These theories are: (1) a disenchanted metaphysics, (2) a theory of instrumental reason, (3) a moral psychology centered on the concept of individual responsibility, and (4) a general view of society as a sum of contractual relationships. The metaphysics will be analyzed in the writings of both Sorai and Seiryō; the remaining three are characteristic of Seiryō’s thought only. The essay will suggest that the inflexion that Seiryō gave to the metaphysics he inherited from Sorai allowed him to embark on the exploration of various philo- sophical theories not found in Sorai’s works. Philosophical dimensions of episte- mology, moral psychology, and the social theory that are explored, in a straightforward manner, in Seiryō’s works were closed in Sorai’s thinking by his own deep-seated conservatism and epistemological pessimism. While these theories were proposed by two self-styled Confucian scholars ( jusha) who argued with the vocabulary inherited from the Confucian classics, they obviously went in very novel directions. This essay examines these theories because they constitute the bedrock, or the basic assumptions, on which modern political theories can be built. Since this is obviously a controversial assertion, the first section of this essay will be devoted to an explanation of the notion of “modern political theories,” something often neglected or examined feebly in previous attempts to elucidate the modern dimension of the worldviews proposed by some Tokugawa period thinkers. Chapter 7 The Philosophical Moment Between O GYŪ Sorai and K AIHO Seiryō: Indigenous Modernity in the Political Theories of Eighteenth-Century Japan? Olivier Ansart O. Ansart (*) Department of Japanese Studies, University of Sydney, Sydney, NSW 2006, Australia e-mail: olivier.ansart@sydney.edu.au