Group doxastic rationality need not supervene on individual rationality

There is a strong formal analogy between proposition-wise super-venience of collective doxastic rationality on individual doxastic rationality and supervenience of social choice functions on individual choice functions. In light of this analogy, the basis for List and Pettit's impossibility theorems can fruitfully be compared with the basis for Arrow's. This helps to explain why List and Pettit can derive no impossibility theorem for set-wise supervenience. However, there are empirical reasons for doubting that set-wise supervenience of collective doxastic rationality on individual doxastic rationality is necessary; a systematic feedback relationship between the former and some individual behavioral dispositions is probably sufficient to dissolve mysteries about group agency. Group doxastic rationality need not supervene on individual rationality.