At the turn of the eighteenth to the nineteenth century, both “the social” and “the biological” emerged as possible new scientific objects within a web of interactions, mutual resonances and common difficulties and problématiques. It would take many more years for these to become distinct and delineated disciplinary fields that were anchored within institutional frameworks. I discuss Lamarck’s part in this process from two angles: (1) the emergence of “biology” within a multilayered context of both novel and existing institutions, political and ideological frameworks, contemporaneous theoretizations and practices concerning “organization,” “self-organization,” “life”; and (2) the possible impact of “biology” and its Lamarckian components as both implicit and explicit horizons of convergence of investigations during the nineteenth century.