Many years ago I have written my PhD thesis about the question how to explain human actions. At the end of my thesis I thought: this is all about individuals but how about groups? Can we explain what groups do from a kind of group intentions just as we can understand individual actions with the help of the agent’s individual intentions (plus his or her beliefs)? In my thesis I wanted to dedicate a chapter to the problem but I dropped it. Nevertheless it stayed in my mind. Actually, I was not the only philosopher who found the issue intriguing. Twenty years ago the theme was rather new, but since then more and more philosophers in the field of analytical philosophy have got their teeth into it, like Raimo Tuomela, Margaret Gilbert, Michael E. Bratman, John R. Searle and Seumas Miller, to mention a few names. One of the most important contributors to this subject is Bratman.
According to Bratman, just as an individual agent has intentions that guides his or her actions, also group behaviour is led by a kind of common intentionality – at least if we talk about small groups. He calls this common intentionality “shared intention”. Say, so Bratman, you and I are painting a house together. It’s not just that each of us is painting on his own, but we coordinate our painting in some way. You scrape the old paint and I paint what you have scraped. You buy the brushes and I buy the paint. We check what the other has promised to do; etc. If this is the case, we have a shared intention, namely in the sense that each of us has the appropriate attitude and that these attitudes and the way they are put into practice are interrelated. We can compare this with the way an individual coordinates what she does over time, for instance when she would paint her house alone: “Thus does our shared intention help to organize and to unify our intentional agency in ways to some extent analogous to the ways in which the intentions of an individual organize and unify her individual agency over time.” (Bratman, 1999: 110-111; quotation on p. 111). Elsewhere Bratman says it this way: “... shared intention ... involves intentions of the individuals whose contents appeal to the group activity” (2014, p. 12). We can compare this sharing an intention with the case that my neighbour and I are painting our houses – we have two semi-detached houses –, but we haven’t consulted on the matter. Then, in my words, my neighbour and I have the same intention but we do not have a shared intention.
However, do we really need a shared intention in order to explain what two people do that are painting a house together in the way described by Bratman? The problem is that Bratman doesn’t say who you and I in his sample are, which suggests that his analysis applies to every two (or maybe three or four) people who form a painting group or another task group doing a job together.
So, let’s say that I want to paint my house, but it is too much work for me. Therefore I hire a hand in order to help me. Together we paint the house, exactly in the way described by Bratman. Then we have a painting group in the sense of Bratman, but does this group and do the people making up the group have a shared intention? On the face of it the shared intention is “painting the house”, and indeed, what I do can be understood in this way:
(1) I have the intention to paint the house.
(2) I think that I can paint the house only, if I hire a hand to help me.
(3) Therefore I hire a hand who helps me painting the house.
(4) Together we paint the house.
Does the hand share my intention to paint the house? I think that what he does can be better understood in this way:
(1) The hand has the intention to earn money [since to hire himself out as a hand is his work].
(2) The hand thinks that he can earn money by helping me painting the house.
(3) Therefore the hand hires himself out to me for this reason.
(4) Together we paint the house.
What this example shows is that for me – the owner of the house – the supposed shared intention is what I want to bring about but for the hand it is a means for another intention, namely earning money. In a certain sense we can call a means also an intention (at least often we can), and then we could say that hiring himself out contains the intention to paint the house, but even if we accept this, we must admit that for the hand this intention is on another explanatory level than it is for me. Therefore I think that my counter-example contains the case of a group of two people who cooperate and act together but who don’t share an intention in the way conceived by Bratman. The upshot is that it is not a shared intention that explains what a group does. The problem here is not finding a common goal that binds the members of a group together but to unravel why these members let themselves bind.