Eric Jabbari examines Pierre Laroque's contribution to the rise of the French welfare state, namely his role as the architect of the social security plan which was adopted by the provisional government in 1945. The conception of the Laroque Plan was a product of his work as a civil servant and social policy expert, and it reflected the diverse combination of influences: his background in administrative law and his onetime support for the corporatist management of industrial relations. These experiences were all the more notable since they were marked by his belief in the necessity of an increased state interventionism which was mitigated by administrative decentralisation. The purpose of social policy, in his mind, was to cultivate social solidarity, a task which could best be achieved if the beneficiaries of this policy could be encouraged to participate in its implementation. These concerns remained central to his conception of the state and society long after he lost his enthusiasm for corporatism, and contributed to the shape of post-war social security.