Lifelong learning has become one of the keys to making workers' career paths more secure at both the French and the European policy level. However, the implementation of these policy lines raises delicate questions as to how the responsibility for vocational training should be shared among employees, employers and public institutions. The capability approach is used here to elucidate the ambiguous relationships between responsibility and freedom that characterized French training reforms in 2004. The study, based on quantitative and qualitative surveys in which employers and their employees were consulted, shows that the environment provided by the company contributes more decisively than employees' previous training and career paths to the capability of the latter to attend vocational training and develop professionally at work. Relying on these empirical findings, it proposes a scheme for a capability-based conceptualization of professional development. (Contains 1 figure, 6 footnotes and 1 table.)