 The theoretical background of Heresy, Yes – Conspiracy, No was not limited to the analysis of the specific means that a democratic society could use to protect itself from internal totalitarian movements without impinging upon legitimate civil liberties, but involved the general conception of the absolute status of the right of liberty and the legitimacy of constraints upon freedom. In a subsequent work titled The Paradoxes of Freedom, Hook confronted the Jeffersonian theme of a right to liberty as an absolute and inalienable right. As a pragmatist, Hook argued that moral rights, like legal rights, could not be absolute, whether grounded in God or Nature. Rather, Hook sought to show how the language of rights presupposed obligations of other persons to protect a right and that these obligations to protect the rights of the individual person were derived from shared human interests in social life. It followed that although rights for Hook could not be reduced to utilities, preferences or expressions of emotive attitude, all rights, including the right to liberty, were defeasible by other values or interests. Thus, a right to liberty could be overridden by the need for a society to protect itself. This is evident when a person’s right to liberty is denied and he is imprisoned after committing a crime. The logic of the defeasibility of absolute rights, however, would also imply that the right of a citizen to hold a national security clearance or a job with a nation’s intelligence agency could be limited by reference to the value of national security. Hook’s practical position was buttressed by his theoretical account of the pragmatic nature of the concept of liberty. The pragmatic account of liberty, however, was not a rationalization for Hook’s political advocacy. The interpretation of natural rights as admitting of limitations upon rights by reference to other values is a constant aspect of the approach that pragmatism offered to the traditions of absolutism and imprescriptability on natural or human rights.