Abstract: Nourished in the tradition of Hegelian Idealism and Comtean Positivism, the concept of "social organism" became an important part in the Victorian political and social thoughts. Through the articulation of numerous theorists, not only was it endowed with rich meanings and explanatory potentials, but was also employed as a powerful rhetorical tool in the Victorian political debate on social reform at the end of the 19th century. The concept of "social organism" first entered the discourse of Herbert Spencer and his disciples to defend their individualistic notion of natural rights and free competition against the power of the state. Later, Spencer's critics formulated more authoritarian interpretations of the concept, paving the way for the institutionalization of public education, charity, urban governance and other public affairs. This eventually led to the re-conceptualization of "social organism" by new-liberalists into a concept that justified social reform, welfare system and state intervention. In the meantime, "social organism" gradually lost its multiple and fluid meanings, ending with a dominant form of explanation that marginalized others. This intellectual event had been successful in introducing the concept of "social organism", previously alien to liberalism, to the nineteenth-century liberal effort of imagining a more cohesive, mutually-dependent society, while also enabling its intellectual participation in the transformation of British society from an industrial kind glorifying laissez-faire principles and individualsim, to a welfare society laying more emphasis on equity and the state's duty for the well-being of the citizens. This study adopts Quentin Skinner's "Cambridge School" method of conceptual history to examine the evolution of the concept of "social organism" during the Victorian period. It serves the purpose of providing a historical narrative of the shifts in the 19th century British liberal political and social ideas.

Key words: conceptual history, social organism, Victorian Social Reform, British Liberalism, Herbert Spencer