In 1989 Oxford University Press launched a new programme of monographs in moral philosophy entitled the ‘Oxford Ethics Series’. Given that the series' editor is Derek Parfit it is unsurprising that the books published to date feature rigorous analysis and argumentation regarding the nature of reasons and requirements. Perhaps by way of intended commitment to this profile, the following brief statement appears on the cover of the first volume (Shelly Kagan'sThe Limits of Morality): ‘The books in the series will contain philosophical arguments about morality or rationality. The aim will be to make undeniable progress’.