Joint Action:

The Question

contrast-case

Introduces the question around which this module is organised. Getting a pre-theoretical handle on joint action is best done by contrasting joint actions with actions that are merely individual but occur in parallel. (The method of contrast cases is familiar from Pears (1971), who used contrast cases to argue that whether something is an ordinary, individual action depends on its antecedents.)

The Simple View

The Simple View is an answer to the question, What distinguishes genuine joint actions from parallel but merely individual actions? According to the Simple View, two or more agents perform an intentional joint action exactly when there is an act-type, φ, such that each of several agents intends that they, these agents, φ together and their intentions are appropriately related to their actions.

The Circularity Objection

According to the Simple View, what distinguishes a joint action from parallel but merely individual actions are the agents’ intentions that they, these agents, act together. But does invoking acting together make this idea circular?

The Circularity Objection Again

According to the Circularity Objection, the Simple View fails to adequately answer to the question, What distinguishes genuine joint actions from parallel but merely individual actions? Here we consider a deeper reply to the Circularity Objection.

Walking Together in the Mafia Sense

contrast-case simple-view

Does Bratman’s ‘mafia case’ provide a reason to reject the Simple View?

From Individual to Joint Action

Provides an alternative introduction to the question around which this module is organised.

Walking Together in the Mafia Sense

contrast-case simple-view

Does Bratman’s ‘mafia case’ provide a reason to reject the Simple View?

Walking Together in the Tarantino Sense

contrast-case simple-view

The Simple View, having survived the objection that it involves circularity and Bratman’s ‘mafia’ objection, now faces a yet more challenging objection. Apparently the Simple View cannot distinguish between all the contrast cases that an account of shared agency must distinguish. (Contrast cases are pairs of cases where one involves shared agency and the other does not and which are otherwise as similar as possible).

Bratman on Shared Intention

Bratman shared-intention

The leading, best developed account of shared intention is due to Michael Bratman. What are the main features of his account?

Two Objections to Bratman

Bratman shared-intention simple-view

Searle and Velleman have offered objections to Bratman’s account of shared intention. (These are also objections to the Simple View.) Are Bratman’s replies successful?

Shared Intention: A Placeholder

intention shared-intention

Most philosophers agree that a notion of shared intention is needed to characterise shared agency. The idea is that shared intention stands to joint action as ordinary, individual intention stands to ordinary, individual action. But what is shared intention?

Why Not Take ‘Shared Intention’ Literally?

intention shared-intention

On most accounts, shared intentions are neither shared nor intentions. But why not take the term literally? Intentions can be shared in the sense in which Ayesha and her best friend share a name. (This would yield a version of the Simple View.) Or perhaps they can be shared in the sense in which Ayesha and her broth share a mother.

Recap: Bratman on Shared Intention

Bratman shared-intention

The leading, best developed account of shared intention is due to Michael Bratman. Here we recall the main features of his account.

A Counterexample to Bratman

contrast-case shared-intention Bratman

No one has yet offered a convincing counterexample to Bratman’s account of shared agency in print. I think there is one, though. If successful, the counterexample motivates considering alternative, more exotic approaches.

Commitment in Shared Agency

commitment shared-intention Gilbert Roth

Are there forms of commitment which are somehow associated with shared intention? Margaret Gilbert and Abe Roth (among several others) have argued that there are. What are the key features Gilbert identifies, and what arguments does Roth offer?

The Objection From Contralateral Commitment

commitment shared-intention Gilbert Roth

A premise linking shared intention with contralateral commitments provides the basis for an objection against Bratman’s account (among others’ accounts) of shared intention. What is the objection and should we accept it?

Gilbert on Joint Commitment

commitment joint-commitment Gilbert

Can we give a reductive account of the sort of commitments associated with shared intention? If not, how should we understand it? In particular, is a joint commitment a commitment that two or more people have collectively? And is Gilbert right that joint commitments have contents of a special form?

Distributive / Collective / Shared

logic

We need a three-fold contrast between distributive, collective and shared.

Are There Joint Commitments?

commitment joint-commitment Gilbert

Do joint commitments exist?

Aggregate Animals, Aggregate Subjects

aggregate-subject physalia-physalis

What are aggregate subjects? I suggest we think of them on the model of aggregate animals such as Physalia Physalis. But how can such a thing as an aggregate subject exist? Humans do not mechanically attach themselves in the way that the polyps and other animals making up Physalia Physalis do. So how are aggregate agents possible?

Joint Commitment and Shared Intention

commitment joint-commitment Gilbert shared-intention

According to Gilbert, ‘joint commitment underlies a host of central social phenomena in the human realm’ and it is a ‘precondition of the correct ascription’ of acting together, collective belief, shared intention, and more’ (2013, p. 9). What does she mean?

Joint and Contralateral Commitment: Objection to Gilbert on Shared Intention

commitment joint-commitment Gilbert shared-intention

Do joint commitments explain contralateral commitments?

How Are Aggregate Subjects Possible?

aggregate-subject physalia-physalis

How can such a thing as an aggregate subject exist? Cordulas’ imperative: In theorising about joint action, see it from the agents’ point of view(s).

Aggregate Subjects: Recap

aggregate-subject

In what ways might the notion of an aggregate subject help us to understand which forms of shared agency underpin our social nature? To answer this question, we first need to consider a more basic question: How can aggregate subjects exist? In a previous lecture we considered the suggestion (developed by Pettit and List among others) that aggregate subjects arise as a conseuqence of individuals representing them. Why do should we consider other suggestions?

Self-representing Aggregate Subjects

aggregate-subject imaginary-we cordulas-imperative

How can aggregate subjects exist? Humans do not mechanically join to one another in the way that the polyps making up an aggregate animal do. What is the glue that binds an aggregate agent together? One suggestion (developed by Pettit and List among others) is that aggregate subjects arise as a consequence of individuals representing them.

Aggregate Subjects vs Plural Subjects

plural-subject aggregate-subject plural-predication shared

A plural subject is some individuals who collectively have an intention or other attitude. An aggregate subject is a subject with multiple parts that are subjects. How do these differ?

Self-representing Aggregate Subjects Presuppose Joint Action

aggregate-subject imaginary-we cordulas-imperative

Suppose that an aggregate subject exists in virtue of several individuals (self-)representing themselves as that aggregate subject. Could this enable us to understand what distinguishes joint action from parallel but merely individual actions?

Team Reasoning

aggregate-subject team-reasoning Sugden Bacharach

‘You and another person have to choose whether to click on A or B. If you both click on A you will both receive £100, if you both click on B you will both receive £1, and if you click on different letters you will receive nothing. What should you do?’ (Bacharach 2006, p. 35) Team reasoning is a game-theoretic attempt to explain what makes your both choosing A rational. But what is team reasoning? And how is team reasoning relevant to questions about joint action? This unit provides the barest outline. The aim is not to explain, but to make you aware that there’s a body of research in this area.

Schmid’s ‘Charlie Brown Phenomenon’

aggregate-subject cooperation Schmid

The the Charlie Brown phenomenon is ‘the possibility of being intentionally engaged in a joint action in a situation in which overwhelming evidence to assume that the others will not do their part is recognized to exist’ (Schmid 2013, p. 54). What does the existence of this phenomenon suggest about shared agency?

Unbearable Reflectiveness

aggregate-subject parallel-planning

On the leading approaches, exercising shared agency requires knowledge or awareness of others’ intentions, plans, knowledge states or readiness to commit to having these. Schmid suggests, in contrast, that ‘participants in joint action are usually focused on whatever it is they are jointly doing rather than on each other’ Schmid (2013, p. 37).

Parallel Planning

aggregate-subject parallel-planning

In parallel planning, each agent individually makes a plan for all the agents’ actions. Although the very idea of parallel planning may initially appears incoherent, it is fundamental to understanding shared agency. Or so I will eventually argue.

The Simple View Revised

aggregate-subject parallel-planning

Can we use parallel planning to rescue the Simple View? (According to the Simple View, Two or more agents perform an intentional joint action exactly when there is an act-type, φ, such that each of several agents intends that they, these agents, φ together and their intentions are appropriately related to their actions.)

Searle vs Bratman on Cooperation

cooperation Bratman

According to Searle, ‘The notion of a we-intention [shared intention] ... implies the notion of cooperation’ (1990, p. 95). Could this be the basis for an objection to Bratman’s theory of shared agency?

Collective Goals

collective-goal plural-predication

An outcome is a collective goal of two or more actions involving multiple agents just if the actions are directed to this goal and this is not, or not just, a matter of each action being individually directed to that goal.

Cooperation

cooperation

There are several notions of cooperation. One is trade-off cooperation. Although widely ignored, trade-off cooperation matters in the sense that achieving it is a condition on optimally distributing resources. An aim for an account of joint action is therefore to explain in virtue of what two or more agents’ actions can be trade-off cooperative.

Collective Goals and Motor Representations

collective-goal motor-representation

Motor representations can ground collective goals in this sense: in some cases, two or more actions involving multiple agents have a collective goal in virtue of the actions being appropriately related to an interagential structure of motor representations.

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