When Pristino Uxia argued in the Argentinian anarchist daily La Protesta that being trapped by one's inheritance was contrary to anarchist liberty, his aim was not to advocate a fatalistic cul-de-sac from which there was no possible escape. 1 He, like many other anarchists who believed that human beings were in possession of sufficient agency with which to determine their own lives, also identified the means by which people could free themselves from the constraints, both political and biological, which bound them to a degenerate past, a conflictive present and a compromised future. His recognition that atavism and degenerative tendencies existed as recurring phenomena also displayed the profound preoccupation among anarchists that there lay within 'human nature' the seeds of decadence and the root cause of the destruction of progress. Uxia also feared that these powerful negative forces, as José Prat and Ricardo Mella had argued in the Spanish context, placed the anarchist project dedicated to human emancipation and fulfilment in jeopardy. The means by which this negation of a possible anarchist future was to be forestalled would be provided by constructing a careful equilibrium between those factors -both positive and negativethat were understood to be essential in humans and those that were thought to have been acquired through the interaction of heredity and the environment. The resulting libertarian project of amelioration would be brought to term by a combination of traditional anarchist methods of agitation, the written and verbal dissemination of ideas and the transformation of 'the social' in conjunction with the reorganization of the basic foundations that made up human biology. As the old consensus whereby nature would cure all was displaced by a technological process of bodily management, anarchists increasingly accepted the tenets of a cluster of social and scientific techniques ranging from neo-Malthusianism, puericulture and health reform through to eugenics. As part of a pre-figurative undertaking, this optimization of the body through the control of sexuality and eugenics would enhance life for workers in the present and prepare them for a luminous libertarian social order in the future.