 Gilbert has used this mutual obligation criterion to criticize reductive accounts of shared activity in terms of “personal intentions” (1990, 180ff; 2008,499), such as that defended by Bratman. Bratman 1997 acknowledges that mutual obligations are typically associated with the sharing of intentions, but insists that they are not essential. He argues that when present, the obligations are explained in terms of a moral principle that one should live up to the expectations about one’s actions that one has intentionally created in others. This principle, articulated by Scanlon in the context of a discussion about promising, does generally apply to situations where individuals act together and share intentions. (Scanlon’s Principle F is in his 1998, 304. For recent discussion of Scanlon and promising that bears on shared activity, see Shiffrin 2008. For another reductivist response to Gilbert see MacMahon 2005, 299ff. For more recent discussion of mutual obligation, see Roth 2004, Alonso 2009.)