The value of a negatively defined private space is defended as important for the development of personal autonomy. It is argued that negative liberty is problematic when split off from its connection with this ideal. An ethical interpretation of personal autonomy is proposed according to which a private space is one of autonomy’s preconditions. This leads to a conceptualization of privacy that is fruitful in two respects: it permits an account of privacy laws that avoids certain pitfalls, and it serves as a basis for criticizing privacy-related failures of autonomy together with the social forces that produce them. Negative liberty is, furthermore, rejected as an adequate basis for modern law and democracy. Here, too, an ethically defined personal autonomy, of which negative liberty is a precondition, is held to be the most convincing normative foundation. A critical reading of Habermas’ cooriginality thesis is offered in support of this argument.