"Rights are central to the theoretical tradition of liberalism (apart from its utilitarian strand), so that when they are violated in its name, this goes against the grain, so to speak, even if the violations are fully justifed. Marxism, by contrast, displays no such tension. It is ... from its origins committed to an ideal of freedom whose coming realization it labels human emancipation. It has never been similarly committed, as a matter of principle, to the promulgation and protection of rights that, when respected, serve to guarantee freedoms."