First published in 1998, this volume argues that two conditions need to be met for any agreement between people with conflicting desires to count as an unforced one, namely, that the parties argue as if they had equal power and that their antipathy to being coerced exceeds their desire to coerce others. These conditions entail objective moral principles and a theory of justice, modifying and developing Rawls' contractarian theory, but without the veil of ignorance. They support Rawls on basic civil liberties and constitutional liberal democratic government, including religious tolerance, anti-paternalism, anti-racism and anti-sexism, but dispute his Difference Principle, his circumstances of justice, Laws of Peoples, reflective equilibrium, and freedom of conscience as a basic liberty. The book also gives a contractarian account of epistemology, metaethics, education, the rationality of being moral, the rights of animals and other non-persons, and the rights of indigenous peoples. Writers such as Brian Barry, R.S. Peters, Isaiah Berlin, Vinit Haksar, Jurgen Habermas, R.M. Hare, Philip Pettit, Derek Parfit, Michael Smith, Peter Geach, Philippa Foot, Bronwyn Davies, Quentin Skinner and Will Kymlicka are also discussed.