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\title {Joint Action \\ Lecture 04}

Lecture 04

Joint Action

\def \ititle {Lecture 04}
\def \isubtitle {Joint Action}
\textbf{\ititle}: \isubtitle
\iemail %
I want to start with our question again ...
\section{From Individual to Joint Action}
\section{From Individual to Joint Action}
Provides an alternative introduction to the question around which this module is organised.
Let me inform (or remind) you how philosophers standardly think about action ...
‘What events in the life of a person reveal agency; what are his [sic] deeds and his doings in contrast to mere happenings in his history; what is the mark that distinguishes his actions?

Davidson, 1971 p. 43

So what is the mark that distinguishes her actions? The passage that I’ve quoted doesn’t fully answer the question. (You need to know about basic actions too.) But here you can see part of the answer. Davidson holds that the mark is intention. That is not to say we do only things that we intend to---after all, alerting the prowler is something Davidson’s man without intending to do so. Rather, the idea is this. If you intend something, to turn the light on perhaps, and this intention is appropriately related to an event, then that event is an action. (This doesn’t yet tell us which events are actions.)
Brilliant theory, so simple. But what’s missing here? We are focussed entirely on an individual acting alone. There’s a parallel question about joint action: \textbf{What are our doings in contrast to things we merely happen to do in parallel?}
But why are we asking this seemingly quite technical question?


What distinguishes genuine joint actions from parallel but merely individual actions?


Any account of shared agency must draw a line between joint actions and parallel but merely individual actions.


Which forms of shared agency underpin our social nature?

This is the organising question for our project (the project to be investigated in this series of lectures). Of course there will be lots of further questions, but I like to have something simple to frame our thinking and this question serves that purpose.
My hope is that by answering this seemingly straightforward question, we will be in a position to answer the hard question about which forms of shared agency underpin our social nature.

They each intend that
they, the sisters, cycle to school together.

Our task, which we started at the end of last lecture, is to find objections to the Simple View.


shared intention

Our current task: understand what shared intention is.
Why? Because it should help us to characterise what distinguishes joint actions from parallel but merely individual actions.
(These men are having dinner together, unlike those on the table next to them who are eating in parallel but merely individually.)

Bratman’s account


Bratman on Shared Intention

\section{Bratman on Shared Intention}
\section{Bratman on Shared Intention}
The leading, best developed account of shared intention is due to Michael Bratman. What are the main features of his account?
So I wanted to start by showing you his picture.
Bratman (2009, p. 150) starts with our question, What distinguishes ...?
But he immediately goes on to say, ‘Step back: what do we want from an answer to this question?’

‘three main concerns: conceptual, metaphysical, and normative.

‘We seek an articulated conceptual framework that adequately supports our theorizing about modest sociality;

‘... to understand what in the world constitutes such modest sociality;

‘and ... an understanding of the kinds of normativity—the kinds of ‘oughts’—that are central to modest sociality.

‘And throughout we are interested in the relations—conceptual, metaphysical, normative—between individual agency and modest sociality.’

Modest sociality:
‘small scale shared intentional agency in the absence of asymmetric authority relations’

Braman 2009, p. 150

Why is this a reasonable strategy? One consideration is that, developmentally and evolutionarily, modest sociality almost certainly came first. So it is reasonable to hope that if we can understand this, we can build up to more complex cases. Another, related thought is Fred Dretske’s maxim that you don’t know how something works until you know how to build it. It is a reasonable guess that in building agents capable of exercising shared agency, a good first target is to get them started with modest sociality.
Note that this is only a starting point: we are also going to consider large scale joint actions (like electing a president) and very small scale joint actions (like sharing a smile or moving an egg).

the continuity thesis

‘once God created individual planning agents and ... they have relevant knowledge of each other’s minds, nothing fundamentally new--conceptually, metaphysically, or normatively--needs to be added for there to be modest sociality.’

Bratman (2015, p. 8)


What is shared intention?

Functional characterisation:

shared intention serves to (a) coordinate activities,
(b) coordinate planning, and
(c) structure bargaining


Inferential integration... and normative integration (e.g. agglomeration)

Substantial account:

To illustrate: if we share an intention that we cook dinner, this shared intention will (iii) structure bargaining insofar as we may need to decide what to cook or how to cook it on the assumption that we are cooking it together; the shared intention will also require us to (ii) coordinate our planning by each bringing complementary ingredients and tools, and to (i) coordinate our activities by preparing the ingredients in the right order.
The functional characterisation is really important: if we accept it, then it tells a lot about what shared intentions could and could not be. In particular, it either rules out Searle’s account or at least shows that the account is not clearly an account of shared intention because it does not explain how the attitude Searle characterises, the ‘we-intention’ could coordinate activities, coordinate planning and structure bargaining.
inferential integration ... [illustrate with planning example where you have to plan both individual and joint action]
normative integration (e.g. agglommeration)
[illustrate agglomeration for individual case first, then joint]
These points are extremely simple but also extremely powerful. They are powerful because they create problems for many approaches to shared agency. Consider Searle’s view again. He thinks that shared intentions are not intentions but a new, sui generis kind of attitude (which is why he uses the term ‘we-intentions’). If you think this, you have to explain how come the new attitudes are inferentially and normatively integrated with ordinary intentions. (I’m not saying this can’t be done, just that doing it is challenging, and certainly not something that Searle has attempted as far as I know.)
We’ll shortly see how the substantial account is built step by step. But maybe it’s helpful to mention the strategy
creature construction is an idea from Grice ...
the construction ...

step 1

‘Our shared intention to paint together involves your intention that we paint and my intention that we paint.’

Bratman (2015, p. 12)


(Compare the Simple View)

This is roughly what the simple view said This might seem completely innocuous, but it is interestingly controversial.

the ‘mafia case’* motivates ... and painting the house different colours motivates ...

step 2

We each intend that we paint by way of the intentions that we paint* and by meshing* subplans of these intentions.

Given what I said earlier, I don’t think the mafia case actually motivates step 2. But I did provide other cases (the Tarantino walkers and blocking the asile) which do seem to motivate step 2.
star: complication ‘and that the route from these intentions to our joint activity satisfies the connection condition’ \citep[p.~52]{bratman:2014_book}.
On the connection condition: It is ‘the condition that specifies the nature of [the] explanatory relation’ between shared intention and joint action \citep[p.~78]{bratman:2014_book}.. ‘the basic idea is that what is central to the connection condition is that each is responsive to the intentions and actions of the other in ways that track the intended end of the joint action--where all this is out in the open.’ \citep[p.~79]{bratman:2014_book}.
We intend to paint the house, but I blue and you red. Earlier work: I trick you ... In the book: ‘we have a problem. In a case of shared intention we will normally try to resolve that problem by making adjustments in one or both of these sub-plans, perhaps by way of bargaining, in the direction of co-possibility. So we want our construction to account for is standard social­ norm-responsive functioning of the shared intention.’ \citep[p.~53]{Bratman:2012fk}
meshing subplans are required
star: meshing
‘The sub-plans of the participants \emph{mesh} when it is possible that all of these sub-plans taken to­ gether be successfully executed.’ \citep[p.~53]{bratman:2014_book}
So much for step 2; now we come to the last major step (I’m skipping some details.)


step 3

‘there is common knowledge among the participants of the conditions cited in this construction’

Bratman (2015, p. 58)

Why impose the common knowledge condition? Before discussing this [I might have to skip discussion of this, but there is a useful quote on the handout], let me provide a summary of where we are with Bratman’s account.
Why require common knowledge in the construction of shared intention? ‘in shared intention the fact of the shared intention will normally be out in the open: there will be public access to the fact of shared intention. Such public access to the shared intention will normally be involved in further thought that is characteristic of shared intention, as when we plan together how to carry out our shared intention. Since such shared planning about how to carry out our shared intention is part of the normal functioning of that shared intention, we need an element in our construction of shared intention whose functioning supports some such thinking of each about our shared intention.’ \citep[p.~57]{bratman:2014_book}

What is shared intention?

Functional characterisation:

shared intention serves to (a) coordinate activities, (b) coordinate planning and (c) structure bargaining


Inferential integration... and normative integration (e.g. agglomeration)

Substantial account:

We have a shared intention that we J if

‘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 [likewise] …

‘3. 1 and 2 are common knowledge between us’

(Bratman 1993: View 4)

These are the conditions that we have been discussing.
Note that these conditions are offered as sufficient but not necessary. (Bratman originally claimed that they were necessary and sufficient, but nothing in the construction rules out alternative realisations of the functional characterisation of shared intention.)
Are sufficient conditions sufficient for achieving Bratman’s aims? Bratman’s pitch is this. Recall the continuity thesis (‘once God created individual planning agents and ... they have relevant knowledge of each other’s minds, nothing fundamentally new--conceptually, metaphysically, or normatively--needs to be added for there to be modest sociality.’ p.8) Bratman reasons that if we can give sufficient conditions for shared agency that are consistent with the continuity thesis, then our default assumption should be that shared agency does not require concepual, metaphysical or normative innovation.
So if we accept Bratman’s sufficient conditions, then we should also accept the continuity thesis. (There might issues about whether merely sufficient conditions are enough to fulfil his aim of providing a framework for theorising about shared agency; more on this when we come to consider joint action and development.)

Two Objections to Bratman

\section{Two Objections to Bratman}
\section{Two Objections to Bratman}
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?

‘Our shared intention to paint together involves your intention that we paint and my intention that we paint.’

Bratman (2015, p. 12)

‘the team intention ... is in part expressed by "We are executing a pass play." But ... no individual member of the team has this as the entire content of his intention, for no one can execute a pass play by himself.’

Searle (1990, pp.~92--3)


the own-action condition:

‘it is always true that the subject of an intention is the intended agent of the intended activity’

Bratman (2015, p. 13)

\citep[p.~13]{bratman:2014_book} [Note that Bratman *denies* this claim.]
Bratman rejects the own-action condition. He notes that there are cases in which it seems I can intend things which involve others’ actions (e.g. I can intend that my son tidy his room). In his 2015 book (chapter 3, section 1), Bratman considers two arguments for it which do not seem to succeed. I follow Bratman in thinking that there is no reason to accept the own-action condition.
Is the ‘own action’ condition a genuine requirement on intending.

Is it a genuine requirement?

So are we done with the objections? Not quite!
A further problem arises from Velleman’s observation about intentions ...

the settle condition:

‘intentions . . . are the attitudes that resolve deliberative questions, thereby settling issues’

Velleman (1997, p. 32)

If we accept the settle condition, then there is a challenge to Bratman: I can only rationally and knowingly intend that we paint if I can settle whether we paint; and likewise for you. But it seems that, in many ordinary cases, I can’t unilaterally settle whether we paint. So, it seems, I can’t intend that we paint without relevant irrationality or ignorance. \citep[pp.~64--5]{bratman:2014_book}
How can we meet this challenge?
Is the settle condition a genuine requirement on intending.

Does Bratmans’s view
violate the settle condition?

A solution?:

(a) if we both do as we intend, we will paint

(b) our intentions that we paint are interdependent*

Strictly speaking, what is required is persistence interdependence ...
Our intentions have \emph{persistence interdependence} just if (a) each of us ‘will continue so to intend if, but only if the other continues so to intend’ and (b) ‘there is this interdepen­dence because each will know whether or not the other continues so to intend, and each will adjust to this knowledge in a way that involves responsiveness to norms of individual plan-theoretic rationality.’ \citep[p.~65]{bratman:2014_book}

(The persistence of my intention is interdependent with the persistence of yours, and this is because ...)


In conclusion, ...
  • Bratman’s theory of shared intention involves interconnected planning.
  • Neither Searle’s nor Velleman’s objection succeeds.
  • Bratman’s account is excellent and it is difficult (but perhaps not impossible) to provide convincing objections to it. If it enables us to answer our question about distinguishing parallel from joint, we can then go on to explore its consequences for normative aspects of joint action.
    But things are perhaps not so simple. counterexample is coming.