Anyone who has ever walked, cooked or crafted with a friend is in a position to know that acting jointly is not just acting side-by-side. But what distinguishes acting jointly from acting in parallel yet merely individually? Four decades of philosophical research have yielded broad consensus on a strategy for answering this question. This strategy is \emph{mechanistically committed}; that is, it hinges on invoking states of the agents who are acting jointly (often dubbed ‘shared’, ‘we-’ or ‘collective’ intentions). Despite the consensus, enduring disagreement remains. The disagreement may be a consequence of the strategy; at least this is plausible enough to motivate considering the prospects for an alternative. Our aim is therefore to ...