This study examines Herbert Spencer's social and political thought by way of his principle of equal freedom. This principle reads, "The liberty of each, limited by the like liberty of each, is the rule in conformity with which society must be organized." ;Basically, this study attempts to demonstrate that Spencer was first and foremost an indirect utilitarian and that equal freedom was the central moral rule of his indirect utilitarianism. An attempt is also made to show how Spencer conceived moral (...) rights as derivations of equal freedom. For Spencer, moral rights were substantive specifications of equal freedom. Like their parent principle, they indirectly promoted happiness. Among other things, my analysis of equal freedom and rights endeavors to clarify how Spencer tried to accommodate a theory of stringent moral rights with utility and how negative freedom and virtue can be seen as compatible features of his theory of freedom. These two themes are meant to comprise some of the most promising rewards of this study. ;This study also explores Spencer's ethical naturalism via G. E. Moore's famous criticisms in Principia Ethica and via some of Henry Sidgwick's critical observations. While Moore's discussion is judged unsatisfactory, Sidgwick's analysis is deemed more successful. ;Finally, this study concludes by examining Spencer's theory of freedom and rights in terms of two fundamental moral rights and in terms of Spencer's vision of utopia. (shrink)