If there is such a thing as reason, it has to be universal - it must work the same way for everyone. Reason must reflect objective principles whose validity is independent of our point of view. To reason is to think systematically in ways that anyone looking on ought to be able to recognize as correct. But this generality of reason is what relativists and subjectivists deny in ever-increasing numbers. And such subjectivism is not just an inconsequential intellectual flourish or badge of theoretical chic. It is exploited to deflect argument and to belittle the pretensions of the arguments of others. The continuing spread of this relativistic way of thinking threatens to make public discourse increasingly difficult and to exacerbate the deep divisions of our society. In The Last Word, Thomas Nagel, one of the most influential philosophers writing in English, presents a sustained defence of reason against the attacks of subjectivism, delivering systematic rebuttals of relativistic claims with respect to language, logic, science, and ethics. His work sets a new standard in the debate on this crucially important question and should generate intense interest both within and outside the philosophical community.