Responsibility for Shared and Parallel Action
To discuss the moral significance of the contrast between shared intentional action and strategic interaction, we need a provisional grasp of what characterizes the former. To this end, we briefly sketch Michael Bratman’s account of shared intention.
This account arguably captures important core features of at least many cases of shared intentional action and we will rely on it in the rest of the chapter (for overviews of other accounts, see Alonso 2018; Tuomela 2018).According to Bratman, several agents’ shared intention plays a role in their shared activity J that is analogous to the role that a single agent’s intention plays in her individual activity. The shared intention coordinates the participants’ planning and acting in pursuit of their J-ing, and it structures their deliberation and bargaining concerning how to J. On Bratman’s account, what plays this role is simply an interpersonal pattern of ordinary intentions and other individual attitudes. There is no need to posit a group agent or an intention that literally belongs to the group as such. In this sense, the account is reductive.
The core of Bratman’s account is what he calls the Intention condition.When we have a shared intention to J—say, to rob a bank—then “[w]e each have intentions that we J; and we each intend that we J by way of each of our intentions that we J [and] by way of sub-plans that mesh” (Bratman 2014: 103). Each thus intends that the bank robbery is brought about by way of each of our intentions that we do this and by way of co-realizable sub-plans for our robbing the bank. When satisfied, this condition ensures that we treat each other as partners or co-participants. Since each of us intends not only that our own intention is effective, but also that the other’s intention is effective, we cannot rationally also intend to bring about the intended end by way of brute coercion that bypasses the other’s agency (say, I cannot intend to handcuff you to the bank’s entrance door against your will, in order to delay the police).
Since each of us intends our subplans to be co-realizable, we also cannot rationally intend to circumvent the execution of the other’s subplan by deception (say, I cannot rationally intend that we rob the bank by my threatening the bank tellers with a handgun if I know that you intend that we rob the bank non-violently, without the use of weapons). Furthermore, if the Intention condition is fulfilled, then each of us will to some extent be disposed to help and support the other in doing their bit to bring about the common end if it becomes necessary (see Bratman 2014: 56—57). When the Intention condition is met, our individual intentions interlock.Bratman’s account of shared intention also specifies that certain supporting beliefs and facts about interdependence be in place, and that the parties have common knowledge that the Intention condition and the other conditions are met. If the shared intention appropriately causes and coordinates the action that is performed together, then it is a “shared intentional activity” according to Bratman, which is a particularly robust form of shared intentional action.
Bratman only claims that his conditions are jointly sufficient for shared intention, but the Intention condition should arguably be taken as a proposed necessary condition. It is this condition that ensures that shared intentional activity is a minimal form of intentional cooperation with respect to the participants’ common end.7
Now, consider the case of us robbing the bank and its customers together and a contrast case where we bring about the same outcome as a result of strategic interaction:
Shared robbery: You and I form a shared intention to rob a bank and its customers. Acting on our shared intention, I point a gun at the bank tellers and force them to hand over the money. You point a gun at the customers in the waiting area forcing them to hand over their jewelry and smartphones. As a result, we jointly intentionally rob the bank and the customers.
Parallel robberies: You and I are two independent robbers who each stake out the same bank. I plan to get the money from behind the counter, while you plan to rob the customers. However, neither of us proceeds because of the risks we each run on our own. The customers are likely to overpower me when I threaten the bank tellers, and the bank employees are likely to warn the police when you threaten the customers. Our chances of success would therefore be significantly higher if we acted simultaneously. As it happens, we each notice the other staking out the bank and we each realize what the other’s plan is (suppose each has earlier overheard the other talking about the possibility of robbing the bank/customers). Expecting the other to follow suit, I form an intention to rob the bank and you form an intention to rob the customers. Acting on my intention, I enter the bank and start to threaten the bank tellers. Acting on your intention, you follow suit and start to threaten the customers. As a result, I rob the bank intentionally and you rob the customers intentionally. Because of the interdependence between our actions, my robbery of the bank and your robbery of the customers are both collective effects of our combined actions.
In Shared robbery, that we rob the bank and the customers—“that we J” in Bratman’s account— is a common end that we are tracking together in virtue of our shared intention. In Parallel robberies, only I have the end that the bank is robbed as a combined result of our actions, while only you have the end that the customers are robbed as the combined result of those same actions. Of course, if we had the opportunity to communicate in Parallel robberies, it is likely that we would acquire or form a shared intention to rob the bank and the customers, making our actions part of one shared intentional robbery. But suppose we do not.
A moment’s reflection on these cases shows that in both cases you and I are collectively responsible for the outcome.
In both Shared robbery and Parallel robberies each of us is clearly morally responsible and blameworthy for the bank and the customers being robbed. Because of our awareness of the interdependence of choices and actions in Parallel robberies, each of us knowingly brings about—has control over—not merely our own intended end, but also the other’s distinct intended end. If knowingly bringing about an outcome is sufficient to intentionally bring it about, then each also intentionally brings it about that both the bank and the customers are robbed in Parallel robberies. In Shared robbery, we each have a similar kind of awareness of and control over the total outcome, but in addition each intends that the total outcome is brought about. It follows that shared intentional action, while sufficient for collective responsibility, is not necessary for it.According to Bratman, a shared intention can play a “linking role” that “may make us each in some way responsible for the shared activity that ensues, and not just each individually responsible for our specific contribution [...]” (1997: 32). What Parallel robberies shows is that a very similar linking role can be played by our awareness of the situation and our strategic intentions. A shared intention is not necessary for agents to be collectively responsible for the collective effect of their combined actions.
Contrary to what some philosophers have assumed then, there is no essential or necessary connection between shared intentional action and collective responsibility for outcomes. Seumas Miller is mistaken when he submits that what we call collective responsibility “presupposes, and is heavily reliant on, the notion ofjoint [intentional] action” (2001: 234). Similarly, in light of examples of what seems to be shared intentional wrongdoing, Steven Sverdlik first correctly submits that “each is responsible for the result precisely because each is responsible for an action aiming at this result” (1987: 67). But he then goes on to mistakenly claim that “it is only when more than one person intends the result that responsibility for it is collective” (1987: 67).8
It is telling that the few accounts of “shared intention” that have been explicitly developed to make sense of collective responsibility—and not to understand shared agency as such—in fact do not require the parties to each intend the result for which they may end up being collectively responsible.
For example, Brook Sadler’s account of shared intention allows for cases where the participants “do not see their respective actions as contributing toward a common goal or activity” (2006: 126). Similarly, on Christopher Kutz’s account, “a set of individuals can jointly intentionally G even though some, and perhaps all, [...] do not even intend to contribute to G, but only know their actions are likely to contribute to its occurrence” (2000: 103; for discussion, see Blomberg 2016b: section 3).However, the fact that we are collectively responsible for the outcome in both Shared robbery and Parallel robberies does not imply that our blameworthiness for bringing about the outcome is the same. In the next section, we consider two possible arguments for the idea that—other things being equal—agents are more blameworthy for shared intentional wrongdoing than for intentional wrongdoing that is the result of parallel action.9
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