Supposition and Choice: Why ‘Causal Decision Theory’ is a Misnomer

This paper has as its topic two recent philosophical disputes. One of these disputes is internal to the project known as decision theory, and while by now familiar to many, may well seem to be of pressing concern only to specialists. It has been carried on over the last twenty years or so, but by now the two opposing camps are pretty well entrenched in their respective positions, and the situation appears to many observers (as well as to some of the parties involved) to have reached a sort of stalemate. The second of these two disputes is, on the other hand, very much alive. While it has been framed in decision theoretic terms, it is definitely not a dispute internal to that enterprise. It is, rather, a debate about the very coherence of the notion of objective value, and as such touches on issues of central importance to, for example, meta–ethics and moral psychology. I think that this second debate deserves more attention from the general philosophical public than it has so far received. That is one of the motivating reasons for this paper. If this debate has received less attention than it deserves, that may be because it centers around a certain rather technical looking argument presented within a formal framework, on a topic that has not traditionally been approached in that way. In fact I see it as a striking example of the right way to use formal methods in philosophical argumentation: to clarify rather than to obscure, to present a particular argument more succinctly and more precisely than could be done informally, and to do so in a way that lays bare the presuppositions and premises of the argument for everyone to see.