Group Agency and Supervenience

Can groups be rational agents over and above their individual members? Group agents are distinguished by their capacity to mimic the way individual agents act, and this capacity must 'supervene' on the group members' contributions. This chapter argues that, for a group to be rational, its judgment on a particular proposition must be a function of their individual sets of judgments across many propositions, not of the members' individual judgments on that proposition: the supervenience relation must be 'setwise', not 'proposition-wise'. This preserves the individualistic view that group agency is nothing mysterious, but also suggests that a group agent may hold judgments that are not directly continuous with its members' corresponding individual judgments.