Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

The incomparability of two items is thought to pose a problem for making justified choices and for consequentialist theories that rely on comparing states of the world to judge the goodness of a particular course of action. In response, it has been argued that items thought incomparable by one of the three standard relations, ‘better than’, ‘worse than’ and ‘equally good’, are instead comparable by some fourth relation, such as ‘roughly equal’ or ‘on a par’. Against such accounts, this article (...) argues that values in virtue of which comparisons are made can be ‘clumpy’ and that in comparisons involving clumpy values, we have no reason to accept ‘roughly equal’ or ‘on a par’ as distinct from ‘equally good’. The article supports the possibility of incomparability by arguing for an interpretation of incomparability as an instance of incommensurability. (shrink)

This paper argues for the existence of a fourth positive generic value relation that can hold between two items beyond ‘better than’, ‘worse than’, and ‘equally good’: namely ‘on a par’.

Can quite different values be rationally weighed against one another? Can the value of one thing always be ranked as greater than, equal to, or less than the value of something else? If the answer to these questions is no, then in what areas do we find commensurability and comparability unavailable? And what are the implications for moral and legal decision making? This book struggles with these questions, and arrives at distinctly different answers.".

This paper is the introduction to the volume. It gives an argumentative view of the philosophical landscape concerning incommensurability and incomparability. It argues that incomparability, not incommensurability, is the important phenomenon on which philosophers should be focusing and that the arguments for the existence of incomparability are so far not compelling.