Derek Parfit is one of the most important ethicists of our time. I’m sure that his Reasons and Personswill soon challenge Kripke’s Naming and Necessityin the number of philosophy dissertations it has influenced.
It appears that the best was yet to come. On What Mattersis Parfit’s Magnum Opus. Some have argued that this tome (and I mean tome—I skipped the gym and just curled volumes 1 and 2) is the most important work in moral philosophy for over a century. I’m not sure if it deserves that level of prestige, but it certainly is a text that attempts to revolutionize ethical reflection by showing how much seemingly oppositional ethical theories have in common. Parfit is an unapologetic rationalist—an unstylish ethical position in our current philosophical climate. Parfit argues that there does indeed exist objective ethical criteria whereby one may judge an action to be right or wrong. This is not a new position. Many have tried to appeal to a religious authority to argue this point. What makes Parfit unique is that his argument is both convincing and secular. How does he do this? Read the text—you will not be disappointed.
The book is very long—but, as Peter Singer states in his review, one could just read the first 400 pages and walk away with the gist of Parfit’s argument. This is necessary reading for anyone interested in ethics. Highly recommended.