Rational Preferences and Reindividuation of Relevant Alternatives in Decision Theory: Towards a Theory of Representation

In this essay, I will examine Broome’s argument in Weighing Goods (1991; sections 5.4 and 5.5) that aims to show that moderate Humeanism, according to which any coherent sets of preferences should be rationally acceptable, is not a sustainable view of decision theory. I will focus more specifically on the argument Broome uses to support his claim, and show that although it may get some traction, it does not undermine moderate Humeanism as we know it. After reconstructing Broome’s argument, I argue that standard decision theory supposes that the representation of a decision problem fully captures what is relevant to the agent, and therefore has nothing to say about the legitimacy of the representation in question. I argue that although Broome’s criticism does not jeopardize moderate Humeanism, it does pave the way for a new area of research in decision theory.