Shared intention and the doxastic single end condition

What is required for several agents to intentionally φ together? I argue that each of them must believe or assume that their φ-ing is a single end that each intends to contribute to. Various analogies between intentional singular action and intentional joint action show that this doxastic single end condition captures a feature at the very heart of the phenomenon of intentional joint action. For instance, just as several simple actions are only unified into a complex intentional singular activity if the agent believes or assumes that there is a single end that each action is directed to, so several agents’ actions are only unified into an intentional joint activity if each agent believes or assumes that there is a single end that each intends to contribute to. Influential accounts of intentional joint action, including Christopher Kutz's and Michael Bratman's, implicitly include this condition only if participants must intend to contribute to the end under the same conception. While such a requirement successfully rules out some counterexamples, it also makes the accounts unable to appropriately accommodate and explain clear cases of intentional joint action that they ought to be able to accommodate and explai