by Stephen A. Butterfill
Joint action is a familiar feature of everyday life. Paradigmatic cases include moving objects together, walking together and playing piano duets. Many joint actions comprise two or more actions involving multiple agents which are purposive in this sense: among all of their actual and possible outcomes, there is one or more to which the actions are collectively directed. One challenge for an account of joint action is to provide a framework for explaining in virtue of what actions involving multiple agents are collectively directed to outcomes. A familiar way to meet this challenge is by appeal to one or another notion of shared intention. In this paper we show that more is needed to fully meet the challenge. In some cases, actions involving multiple agents are collectively directed to an outcome not in virtue of any kind of shared intention but in virtue of a certain interagential structure of motor representations. Further, some joint actions are collectively directed to outcomes partly in virtue of this interagential structure of motor representations. This suggests that the building blocks needed for constructing an account of joint action may include not only shared intention but also a certain interagential structure of motor representations. We conclude by discussing some consequences for accounts of shared intention.