What Is Joint Action? Bratman’s Account

Lecturer: Stephen A. Butterfill

On the leading, best developed account of joint action (Bratman’s), joint action requires shared intention and shared intention requires mindreading abilities, including insight into others’ plans and intentions.

• stream
• slides only

Notes

Consensus on Shared Intention

There is a broad consensus that joint action involves shared intention:

‘I take a collective action to involve a collective [shared] intention.’ (Gilbert, 2006, p. 5)

‘The sine qua non of collaborative action is a joint goal [shared intention] and a joint commitment’ (Tomasello, 2008, p. 181)

‘the key property of joint action lies in its internal component […] in the participants’ having a “collective” or “shared” intention.’ (Alonso, 2009, pp. 444–5)

‘Shared intentionality is the foundation upon which joint action is built.’ (Carpenter, 2009, p. 381)

‘I will … adopt Bratman’s … influential formulation of joint action … each partner needs to intend to perform the joint action together ‘‘in accordance with and because of meshing subplans’’ (p. 338) and this needs to be common knowledge between the participants.’ (Carpenter, 2009, p. ][p.\ 281)

But what is shared intention?

Bratman’s Account

In characterising shared intention, Bratman first identifies its function. On his account, shared intention serves to coordinate activities, coordinate planning and structure bargaining (Bratman, 1993; Bratman, 2014).

If this is what shared intentions are for, what could they be? Bratman argues that the following are collectively sufficient conditions for you and I to have a shared intention that we J:

1. (a) I intend that we J and (b) you intend that we J

2. I intend that we J in accordance with and because of la, lb, and meshing subplans of la and lb; you intend that we J in accordance with and because of la, lb, and meshing subplans of la and lb

3. 1 and 2 are common knowledge between us’ (Bratman, 1993, p. View 4).

In more recent work Bratman has added these further conditions:

1. The persistence of each intention in conditions 1 and 2 is interdependent with the persistence of every other such intention (Bratman, 1997, p. 153; Bratman, 2006, pp. 7–8; Bratman, 2009, p. 157; Bratman, 2010, p. 12)

2. We will J ‘if but only if 1a and 1b’ (Bratman, 1997, p. 153; Bratman, 2009, p. 157).

The common knowledge condition, #3 above, is extended to include these further conditions, #4 and #5. The view has been further elaborated in Bratman (2014).

References