This book seeks to systematize and weigh the different arguments, theoretical-architectural approaches, methodological contributions and proposals for foundation and practical application, both of the Ethics of Discourse in its Apelian version, and of the Ethics of Liberation in its Dusselian version. The above is aimed at being able to evaluate the possibility or not of a potential synthesis and mutual enrichment of both theories, and pursues the goal of determining the capacity of both proposals to found intersubjectively binding rational moral norms and their respective possibilities of historical-political application. .