Intrinsic Utility's Compositionality

To compare the options in a decision problem, a common method evaluates for each option the world that would result if the option were realized. This paper argues that one evaluation of an option's world, intrinsic utility, is compositional given a division of an option's world according to the option's consequences and other events. The argument first justifies the norm that an ideal agent should be intrinsically indifferent between two options' worlds given that she is intrinsically indifferent between the options' consequences. Then it uses this norm and the existence of intrinsic utilities respecting intrinsic indifference to establish intrinsic utility's compositionality. The results regulate human agents when they approximate ideal agents in pertinent respects. The paper begins with a general explanation of compositionality; the related phenomena of interchangeability, complementarity, and independence; and the effect on compositionality of context and arrangement of a composite's parts. After arguing for intrinsic utility's compositionality, the paper explains its role in decision theory.