The six lectures gathered in this book by one of the most distinguished contemporary American philosophers discuss from an innovative perspective whether or not ethical judgments can be considered objective. In the first four lectures, given at the University of Perugia in Italy, Putnam considers that ethics are used to solve practical problems, not to establish universal principles, and he argues that ethics are characterized by an objectivity analogous to that of mathematics but that trying to explain the objectivity of mathematics and ethics in ontological terms is a big mistake. Ontology, understood as the part of philosophy that deals with existence, would be the result of a great misunderstanding that has perpetuated under different forms from the Greeks to Quine. In the last two lectures, given at the University of Amsterdam, Putnam puts his reconceptualization of ethics in a historical context and proposes a narrative of intellectual and moral progress based on the succession of three enlightenments: the Platonic, that of the 17th and 18th centuries, and John Dewey's Pragmatist. Faced with cultural relativism and an uncertainty that brings an "infinite regression of interpretations" of current postmodern thought, Putnam defends the possibility of justifying in a contextualized way the resolution of problems and conflicts of ethical and political character.