Rationality, Reasoning, and Group Agency

The rationality of individual agents is secured for the most part by their make-up or design. Some agents, however-in particular, human beings-rely on the intentional exercise of thinking or reasoning in order to promote their rationality further; this is the activity that is classically exemplified in Rodin's sculpture of Le Penseur. Do group agents have to rely on reasoning in order to maintain a rational profile? Recent results in the theory of judgement aggregation show that under a range of plausible conditions they do. In a slogan: group agents are made, not born.