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\title {Joint Action \\ Lecture 12}

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Lecture 12

Joint Action

[email protected]

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\def \isubtitle {Joint Action}

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{\Large

\textbf{\ititle}: \isubtitle

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Diagnosis

Too reflective!

Grounded merely on intuitive contrasts!

How can we turn Schmid’s observations into a theory, and thereby overcome the problem of unbearable reflectiveness?

\section{Unbearable Reflectiveness}

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).

At this point I want to consider Hans Bernard Schmid’s diagnosis of why we have failed to understand shared agency. His suggestion is that the leading approaches are mistaken in construing exercises as shared agency as involving reflection on knowledge or awareness of others’ intentions, plans, knowledge states or readiness to commit to having these.

‘participants in joint action are usually focused on whatever it is they are jointly doing rather than on each other. Where joint action goes smoothly, the participants are not thinking about the others anymore than they are thinking about themselves’

\citep[p.~37]{Schmid:2013}

Schmid (2013, p. 37)

I don’t think this observation is an argument or an objection; I’ll treat it as a potential diagnosis that might guide the construction of an alternative.

Let me first remind you of how three accounts show symptoms consistent with Schmid’s diagnosis. In Pacherie’s account, we need beliefs about the others and their team reasoning.

In Bratman’s account we need intentions about others’ intentions ...

Consider Bratman ...

Recall that Bratman proposes sufficient conditions for us to have a shared intention that we J ...

... the idea is then that an intentional joint action is an action that is appropriately related to a shared intention.

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)

Note that the conditions require not just that we intend the joint action, but that we intend it because of each other's intentions, where this is common knowledge.

So we need not just intentions about intentions ...

... also you need to know things about my knowledge of your intentions concerning my intentions.

Of course, these are sufficient not necessary conditions, so we can’t infer from the fact that these conditions require reflection to the conclusion that exercising shared agency always requires reflection.

But Bratman also specifies a functional role; it is necessary (on his view) that shared intentions play this role.

And, as I argued earlier, coordinating planning is unlikely to be possible without knowledge of facts about others’ plans.

So, on Bratman’s view, exercising shared agency in, say, moving a table from here to there involves us considering not only facts about about the table’s size and the space around it but also facts about each other’s intentions and plans.

Gilbert

Although this is less obvious, on Gilbert’s view there is a similar need for awareness of others’ mental states in exercising shared agency.

First recall what Gilbert says about shared intention:

For us to have a shared intention that we φ is for us to be jointly committed to emulate a single body which intends to φ

Second, think about how, on Gilbert’s view, joint commitment is possible. In all the basic cases ...

Joint commitment requires

mutual awareness of expressions of readiness to so commit

On Gilbert’s view, participating in any of the social phenomena she analyses involves expressing readiness to commit, and ...

... and our being mutually aware of these expressions of readiness.

As Gilbert herself notes, this requires thinking thoughts about joint commitment plus other notions used in the analysis (p.~334).

Thus acting together requires thinking about intentions and about joint commitments, and jointly attending to an object requires thinking about joint attention and about joint commitments.

This also has implications for development, by the way.

Consider two-year-old toddlers who cannot yet think about joint commitments and appear insensitive to the possibility of them \citep{Grafenhain:2010zl,hamann:2012_children}. % \footnote{% % See \citet{Grafenhain:2010zl}. % While many recent findings have shown that toddlers’ social cognition is surprisingly sophisticated, it would be a precocious toddler indeed that was sensitive to whether she had the standing to rebuke another party to a joint commitment. % } On Gilbert’s view, it is impossible for there to be mutual recognition between toddler and adult, and it is impossible to act together with a toddler, by, for instance, looking at a book together, sharing a smile, or walking together. This is unexpected given evidence that toddlers appear to spontaneously initiate, and to repair, such joint activities \citep[e.g.][]{Warneken:2006qe,warneken:2013_young}.

Pacherie

‘Two persons P1 and P2 share an intention to A, if:

(i) each has a self-conception as a member of the team T, consisting of P1 and P2 (collective self-framing);

(i’) each believes (i) (group identification expectation);

(ii) each reasons that A is the best choice of action for the team (team reasoning from a group viewpoint); and

(iii) each therefore intends to do his part of A (team reasoning from an individual viewpoint).’

\citep{pacherie:2013_lite}

Pacherie (2013)

see also Sugden (2000); Gold & Sugden (2006); Pacherie (2011)

Step 2b: Pacherie on ‘Shared intention lite’ (best account linking shared intention to team reasoning)

*FORGOT TO SAY IN LAST LECTURE: Does team reasoning or Pacherie’s account meet Searle’s constraint: ‘The notion of a [shared intention] ... implies the notion of cooperation’ Searle (1990, p. 95)? Yes, beautifully

This is needed to deal with the potential objection; and I suggested that belief conditions are needed for all of the conditions as well (otherwise we could have a shared intention while rationally and with justification believing that we do not).

Recall Hans Bernard Schmid’s diagnosis of why we have failed to understand shared agency. How does the Simple View stand with respect to this diagnosis?

Schmid (2013, p. 37)

Simple View

Two or more agents perform an intentional joint action
exactly when there is an act-type, φ, such that
each agent intends that
they, these agents, φ together
and their intentions are appropriately related to their actions.

I think if Schmid’s claim is an objection, it is not an objection to the Simple View.

Recall Hans Bernard Schmid’s diagnosis of why we have failed to understand shared agency. As I said earlier, his suggestion is that the leading approaches are mistaken in construing exercises as shared agency as involving reflection on knowledge or awareness of others’ intentions, plans, knowledge states or readiness to commit to having these.

\citep[p.~37]{Schmid:2013}

Schmid (2013, p. 37)

‘individual agents of temporally extended actions “represent” their own future intentions and actions in the same way in which cooperators represent their partners’ intentions and actions.’

\citep[p.~49]{Schmid:2013}

Schmid (2013, p. 49)

Dominant View: ‘the representation of the participation of the others has a mind-to-world direction of fit.’

Alternative View: ‘the representation of the participation of the others has a world-to-mind direction of fit.’

\citep[p.~38]{Schmid:2013}

Schmid (2013, p. 38)

explain

Ok, this is just an assertion. What’s the argument for it ...

Diagnosis

Too reflective!

Grounded merely on intuitive contrasts!

How can we turn Schmid’s observations into a theory, and thereby overcome the problem of unbearable reflectiveness?

Parallel Planning

\section{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.

A representation or plan is \emph{agent-neutral} if its content does not specify any particular agent or agents; a planning process is agent-neutral if it involves only agent-neutral representations.

Practical vs theoretical reasoning: ‘The mark of practical reasoning is that the thing wanted is \emph{at a distance} from the immediate action, and the immediate action is calculated as a way of getting or doing or securing the thing wanted’ \citep[p.\ 79]{Anscombe:1957ln}. See also \citet[p.\ 1]{millgram:2001_practical}: ‘Practical reasoning is reasoning directed towards action: figuring out what to do, as contrasted with figuring out how the facts stand.’

Some agents each \emph{individually make a plan for all the agents' actions} just if: there is an outcome; each agent individually, without discussion, communication or prior arrangement, plans for that outcome; and each agent’s plan specifies roles for herself and all the other agents.

Our planning is \emph{parallel} just if you and I are each planning actions that I will eventually perform and actions that you will eventually perform, where the resulting plans non-accidentally match.

Two or more plans \emph{match} just if they are the same, or similar enough that the differences don't matter in the following sense. First, for a particular agent's plan, let the \emph{self part} be those steps concerning what will be the agent's own actions and let the \emph{other part} be the other steps. Now consider what would happen if, for a particular agent, the other part of her plan were as nearly identical to the self part (or parts) of the other's plan (or others' plans) as psychologically possible. If the agent's self part would not be significantly different, let us say that any differences between her plan the other's (or others') are not relevant for her. Finally, if for some plans the differences are not relevant for any of the agents, then let us say that the differences don't matter.

The guiding idea behind Bratman's planning theory of shared intention is this: ’shared agency consists, at bottom, in interconnected planning agency of the participants’ (Bratman 2011, p. 11).

‘shared intentional agency consists, at bottom, in interconnected planning agency of the participants.’

(Bratman 2011, p. 11)

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)

parallel planning

You plan our actions, yours and mine, and I plan our actions too

Here, interconnected planning is planning where facts about your plans feature in my plans & conversely. I think there are some cases for which interconnected planning just does not seem like a good approach.

Suppose you and I are tasked with moving this table through that door. In doing this, must my plan take into account facts about your intentions as well as about the weight of the table, width of the door &c? This case has some special features: (i) there is a single most salient route for the table given our objective; (ii) there is a single most salient way of dividing up the roles between us. I suggest that, in this situation, neither of us needs to form a plan involving the others' intentions. The situation makes this redundant. All we have to plan is how two people in our situations should move the table through the door.

To a first approximation, then, what the situation seems to call for is not that our plans are interconnected but rather that we each make a plan for the table-moving action as a whole. This is inspiration for the view that we might arrive at sufficient conditions by reflecting on parallel rather than interconnected planning ...

‘shared intentional agency consists, at bottom, in interconnected planning agency of the participants.’

(Bratman 2011, p. 11)

Facts about your plans feature in my plans & conversely.

parallel planning

You plan my actions as well as yours, and I do likewise.

So Bratman’s notion of interconnected planning seems not to fit this sort of case. (This is much as Schmid suggests.)

In parallel planning, I plan all of our actions and you do the same. I want to suggest that shared agency sometimes requires only parallel, and not interconnected planning.

Some of you are probably already thinking that the very idea of parallel planning is incoherent, and I will face up to this objection.

But first I want you to suspend disbelief and consider how parallel planning could enable us to coordinate our actions and our plans ...

Suppose you and I are parents about to change our baby's nappy.

This involves preparing the baby and preparing the nappy.

You're holding the baby and I'm nearest the pile of clean nappies, so there's a single most salient way of dividing the task between us.

Preparing the baby is, of course, a complex action ...

Now there are relational constraints on how the baby and nappy should be prepared; how you clean constrains and is constrained by how I prepare the clean nappy (because we don't want to get pooh on it).

\textbf{How do we meet these relational constraints?} The fact that I have a plan for the whole thing and so do you, and the fact that these plans are identical or similar enough that the differences don't matter means that your plan for your actions is constrained by your plan for my actions, which is my plan for my actions. So thanks to our parallel planning---to the fact that we each plan the whole action---your plan for your actions is indirectly constrained by my plan for my actions; and conversely. So: in parallel planning, we meet these relational constraints not by thinking about each other's intentions but by planning each other's actions.

There's just one tiny problem. In supposing that we both make a plan for the whole action, I'm implying, of course, that we each make plans for actions that are not our own. And this seems incoherent, unless perhaps we (the agents performing the action) are irrational or ignorant.

[Don’t say: messes up the two-phase approach below: It seems incoherent because the elements of plans we make are intentions; so, apparently, in making a plan for your action I would end up intending your actions. But I can't intend your actions, I suppose. What can we do?]

agent-neutral practical deliberation

I want to address this problem in two phases.

The first phase concerns practical deliberation. (Here I step back from planning and consider mere deliberation about what should be done [the distinction between practical reasoning and practical deliberation is mentioned in the notes above].) As Millgram says, ‘Practical reasoning is reasoning directed towards action: figuring out what to do, as contrasted with figuring out how the facts stand' \citet[p.\ 1]{millgram:2001_practical}.

I suggest that the reasoning which leads to action can be \emph{agent-neutral}; that is, it can avoid the specification of any particular agent or agents.

To illustrate, suppose that you're having some work done in your flat and have hired an electrician and a decorator. The decorator arrives first. Realising that she will need to work around the electrician, she needs to work out how the electrician will approach the job. Because the decorator is also a skilled electrician, she makes a plan for the re-wiring of your flat. This process of planning has the key features of practical reasoning: it is a matter of figuring out what to do, it involves determining means given ends, and it involves selecting means for various ends in such a way that all of the means can be implemented together.

Now you might say that what the decorator is doing is not really practical deliberation. But note that it is preparation for action. Suppose you find out that the electrician can't make it, so you ask the decorator to stand in as the electrician. She does not have to engage in further planning or practical reasoning; she is already poised to act. So the practical reasoning that she has already done for actions that were to be performed by someone other than her puts her in a position to act immediately.

(Even if you want to say, for some reason, that reasoning concerning actions one believes others will perform cannot be practical, you should recognise that it has some important features of practical reasoning: it serves to put one in a position to act, it involves determining means given ends, it involves selecting means for various ends that can all be implemented together, and it involves adopting a perspective insofar as particular agents' biases and quirks are ignored. These are the features of practical reasoning that matter for my argument.)

So it seems to me it should be uncontroversial that processes of practical deliberation can concern actions that you expect other to eventually perform, and that such practcical deliberation can lead directly to action if it later turns out that it is you who is to perform this action.

Note that in practical deliberation one has a special perspective on the actions; one illustration of this is that you ignore particular agents' biases and quirks, even if these are highly reliable. These can inform prediction but not planning processes. This will be important later.

Agent-neutral practical deliberation has practical applications in coordinating our actions. (Housemates pizza example: agree to make it but then have to leave immediately; shows that practical delibration can occur in parallel ...)

But what attitude results from practical deliberation?

That some of your practical reasoning concerns actions that others will eventually perform does not entail that you have practical attitudes towards their actions.

(Just here we have to be careful with terminology. I am claiming that the decorator makes a plan for actions she believes the electrician will eventually perform. I am not claiming that the decorator plans or intends to perform those actions. Note also that to say the decorator `has a plan' for goals she believes are not her responsibility may be misleading: she has beliefs about how these goals could be achieved (so has a plan in one sense) but she does not have intentions concerning these goals (so lacks a plan in another sense).)

If the agent-neutral plan is to result in me acting, then I need to have some sort of practical attitude towards it.

But since some of the actions it specifies are, I know, actions you will eventually perform, I can't simply intend to implement the plan.

Dilemma:
not intention concerning own action;
and not mere belief, nor intention, that another acts

So here I seem to face a dilemma. [First horn: not intention] It seems that I can't intend it in the ordinary sense because then I'd be intending its parts, and some of its parts are actions that, I know, you will eventually perform. So, apparently, I'm blocked from intending the plan

[Second horn: not belief] On the other hand, if I merely entertain a belief about the plan --- if, for instance, I merely believe that the plan identifies a way we could achieve some goal --- then it's unclear how I could be acting on it at all.

What seems to happen in the case of the dectorator-turned-electrician is that the decorator starts out with beliefs and then, when asked to stand in for the electrician, ends up with intentions.

open-ended intentionsSecond phase: we need to appeal to some ways in which intentions can be open-ended.: whenIt's a familiar idea that intentions can be open-ended with respect to when something intended will be done. For instance, you can intend to visit Cafe Europa without intending to do so on any particular day., and whoIt's also true that intentions can be open-ended with respect to who will act on them.Consider a couple planning some tasks at the start of the weekend: they need to buy bread, to clean the bath, ... At this point, their intention is that one or both of them will do each of these things, but there is no further specification concerning who will act. Now you might say that you can't intend something without settling who will act. But this seems wrong given that (i) the couple's attitudes are practical, and (ii) generate requirements concerning agglommeration. (Even before it's determined who will do what, I know that I'm not going to be able to spend the afternoon in the pub.)[*skip] You might also say that open-ended intentions generate pressure to filling in details. This is true, but the details are not always filled by further intentions. At some point intentions give out and we just act. The point of appealing to the table-moving example was that here there is no need for the intention to specify the agents.I want to suggest that appeal to the open-endedness of intentions will help with the dilemma I had.The problem was, what attitude could I have to another's actions?

The attitude I can have is this: with respect to the whole plan, I intend that we implement it. And with respect to its components, I intend that you or I or we do them.

This seems almost but not quite satisfactory to me. The potential difficulty, I think, is with the idea that, concerning things that will eventually be your actions, I have an intention that is open-ended with respect to whether it is you, me or we who will do those things. This seems unsatisfactory because at some point I may know that you will do these things and I don’t have to concern myself with them; and this will free me to do things that would prevent me from performing actions that are essential for our success but which I know you will perform. By contrast, having an open-ended intention implies that there is still a possibility that I will act and that I am still bound by requirements on agglomeration. \textbf{So as the actions unfold, there must be a point at which I no longer have an intention that is open-ended with respect to who will act because it has become clear that you are to do the thing intended. What do I intend at this point?}

[new] I think there are two possibilities. First: I intend that you perform the action. No problems arise if this is correct.

The second possibility is that I now no longer have an intention concerning this action at all; it simply disappears from the plan. So now I no longer intend the whole thing either (the plan): after all, I can’t rationally intend the whole if I knowingly fali to intend some parts of it. This is an odd result: I lose the intention concerning our action before it is actually complete. But it does not seem fatal. What matters to me is just that parallel planning can result in a pratical attitude without incoherence or irrationality, and that remains true even if it is an attitude which cannot always be sustained throughout the whole action.

[old--no! If open-endedness is retained, why am *I* acting? BUT: still useful to stress the virtue of retaining open-endedness as long as possible.] While this appears to be a deficit of the account, I want to suggest that it is actually a virtue. In changing the nappy, I am always somewhat ready to take on part of your role; to grab the baby if you unexpectedly have a sneezing attack, say. By contrast, when I am merely relying on knowledge about your future actions and planning my own actions in the light of this knowledge, we are not strictly acting as one. So my having intentions concerning actions that I expect you to perform where these intentions are open-ended with respect to who will act is a mark of acting as one. (Note: this applies to my own actions as well; I shouldn’t intend that I do them, but that I or you or we do them.)

So my intentions don't specify who will do what. But they don't need to, because this is already adqeuately specified by the fact that you're holding the baby and I'm nearest the clean nappies. So in this case what determines who does what are the constraints, not the intentions.

tennis doubles vs surgery

You might object (along lines Barry Smith did to a related idea) that parallel planning only makes sense where roles can be swapped. It is fine for tennis doubles, say, but disastrous for surgery where surgeon and nurse have quite different expertise.

But note that parallel planning doesn’t have to reach all the way down. You only have to plan the other’s actions in enough detail to coordinate with them. And of course parallel planning needn’t be---and typically isn’t---the only means by which coordination is achieved.

In general, parallel planning does not require that I plan all of the actions of all of the agents; it only requires that I plan those actions that constrain my own.

What matters is just this: in parallel planning, each agent has a plan which includes some actions that, if things go as they should, will be performed by other agents.

Parallel planning

df.

Each agent individually plans not only her own actions but also those of others.

1. Parallel planning is agent-neutral.

2. Parallel planning results in intentions that are open-ended with respect to who will act.

‘shared intentional agency consists, at bottom, in interconnected planning agency of the participants.’

(Bratman 2011, p. 11)

Facts about your plans feature in my plans & conversely.

parallel planning

You plan my actions as well as yours, and I do likewise.

And parallel planning contrasts with interconnected planning.

This is why, despite appearances, I think the notion of parallel planning is coherent. Without irrationality or ignorance, it is possible for us each to plan all of our actions, yours and mine, and to act on these plans. In doing so we achieve coordination and manifest collective intentionality not by thinking about each other's plans but, more directly, by planning each other's actions.

Diagnosis

Too reflective!

Grounded merely on intuitive contrasts!

I think parallel planning addresses the first of the two obstacles we face.

Have we met Schmid’s requirements? (Not in the way he intends, of course ...)

\citep[p.~37]{Schmid:2013}

Schmid (2013, p. 37)

‘cooperators normatively expect their partners to cooperate; they do not predict their cooperation’

Dominant View: ‘the representation of the participation of the others has a mind-to-world direction of fit.’

Alternative View: ‘the representation of the participation of the others has a world-to-mind direction of fit.’

\citep[p.~38]{Schmid:2013}

Schmid (2013, p. 38)

Parallel planning plus intentions that are open-ended wrt to who meet this requirement.

The Simple View Revised

\section{The Simple View Revised}

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.)

So what?

Now so far I've been arguing only that (i) the notion of parallel planning is coherent, (ii) that parallel planning enables us to coordinate our actions. But that doesn't, by itself, amount to showing that the notion of parallel planning is any more useful than that of interconnected planning. For all I've said so far, it might be that both parallel and interconnected planning play a role in coordinating actions, but neither can be used to give sufficient conditions for intentional joint action. Can I do better?

Simple View

\emph{The Simple View Revised} We intentionally exercise shared agency exactly when ... and: \begin{enumerate} \item we engage in parallel planning; \item for each of us, the intention that we, you and I, φ together leads to action via our contribution to the parallel planning (where the intention, the planning and the action are all appropriately related). % nb: may have to weaken this condition to allow for cases in which there is some parallel planning but then a switch to individual planning (from discussion with Olle). % % these intentions lead to action by way of this planning (that is, for each of us, our intention leads to our actions via our individual contribution to the parallel planning); % \item each of our contributions to the parallel planning results in intentions, some or all of which are open-ended with % respect to who will act; and % \item for each of us, these intentions are also appropriately related to our actions. \end{enumerate}

(Nonaccidental success requires, further, that our parallel planning results in matching plans.)

Two or more plans \emph{match} just if they are similar enough that the differences don't matter in the following sense. First, for a plan in an agent, let the \emph{self part} be those representations concerning the agent's own actions and let the \emph{other part} be the other representations. Now consider what would happen if, for a particular agent, the other part of her plan were as nearly identical to the self part (or parts) of the other's plan (or others' plans) as psychologically possible. Would the agent's self part be significantly different? If not, let us say that any differences between her plan and the other's (or others') are \emph{not relevant for her}. Finally, if for some agents' plans the differences between them are not relevant for any of the agents, then let us say that the differences \emph{don't matter}.

We can save the Simple View.

Recall the objections to it: Tarantino walkers, blocking the asile.

There is something a bit tricky here. If we consider Beatrice and Baldric, or the people walking in the Tarantino sense, I do think their intentions are appropriately related to their actions; that is, we shouldn’t consider such cases as somehow involving deviant causal chains. So I don’t think we can take parallel planning as part of an account of what it is for agents’ intentions to be appropriately related to their actions. Instead I think we have to see it as a further additional condition on the relation between intentions and actions.

Parallel planning gives us an account of how the intentions have to be related to the actions in order for the agents to exercise shared agency.

What about the counterexamples?

Is the Revised Simple View susceptible to the counterexamples we considered?

contrast case: blocking the aisle

Imagine two sisters who, getting off an aeroplane, tacitly agree to exact revenge on the unruly mob of drunken hens behind them by standing so as to block the aisle together. This is a joint action. Meanwhile on another flight, two strangers happen to be so configured that they are collectively blocking the aisle. The first passenger correctly anticipates that the other passenger, who is a complete stranger, will not be moving from her current position for some time. This creates an opportunity for the first passenger: she intends that they, she and the stranger, block the aisle. And, as it happens, the second passenger’s thoughts mirror the first’s.

1. The sisters perform a joint action; the strangers’ actions are parallel but merely individual.

2. In both cases, the conditions of the Simple View are met.

The feature under consideration as distinctive of joint action is present: each passenger is acting on her intention that they, the two passengers, block the aisle.

therefore:

3. The Simple View does not correctly answer the question, What distinguishes genuine joint actions from parallel but merely individual actions?

The conditions of the Revised Simple View are not met. This is because the Revised Simple View requires parallel planning, which involves taking a practical attitude towards the others’ actions. And this is rationally incompatible with the theoretical attitude--merely predicting them--which the strangers blocking the aisle have towards each other’s actions.

parallel planning yields practical unity

In parallel planning, we take a perspective that allows us to see our actions, yours and mine, as having a certain kind of practical unity.

What is practical unity? To illustrate, first consider the case of a single individual.

Imagine someone committed to keeping two or more areas of her life apart, so that she tries to plan separately for each area of her life. When concerned with planning in one area, she treats ongoing and planned actions from other areas of her life almost as if they were the actions and intentions of another agent who is temporarily acting with her body. Actions from other areas of her life feature in her current planning only as constraints to work around or opportunities to exploit. Of course, many of her predictions about her own actions are based on plans she has made when thinking about other areas of her life. But she systematically avoids conceiving engaging in planning for actions that involve different areas of her life; she does not treat her actions as even potentially parts of a single, larger plan. So there is a kind of practical unity that she fails to conceive of the actions which make up her life as having. She never takes perspective one has on actions when engaged in planning for them with respect to all her actions. Instead, at each time she plans for just one area of her life and takes the perspective of an outsider on the other areas of her life.

As this illustrates, the ability to conceive of any our actions as potentially featuring in a single planning process matters partly because it allows us to see them as having a kind of practical unity.

This applies to how you conceive of others' actions, not just your own. Earlier, I argued that you can sometimes engage in practical reasoning (in the context of parallel planning) for not only actions you yourself will eventually perform but also for actions that others will eventually perform. This shows that it is sometimes possible to take the sort of perspective on others’ actions that you would paradigmatically take on your own actions.

I am not suggesting, of course, that you thereby conceive of others’ actions exactly as if they were your own. But nor do you conceive of the others’ actions in quite the way you would conceive of the actions of just any other agent who happened to be passing by. Rather, you conceive of these actions as on a par with your own actions insofar as they all feature in a single planning process. (*thanks to Peter Fossey here:)

What about walking in the Tarantino sense? Recall that there is room for debate about whether this is a counterexample at all. Nevertheless, I want to consider what the Revised Simple View implies about this case.

First allow me to introduce some claims.

Engaging in parallel planning concerning our changing a nappy involves taking a practical attitude (one of intending) towards actions you will perform.

Having interconnected plans concerning our changing a nappy need not involve taking a practical attitude (one of intending) towards actions you will perform. (I may consistently regard your intentions and actions merely as opportunities to exploit and constraints to work around.)

Agents can have interconnected plans while thinking of each other's actions merely as opportunities to exploit and constraints to work around.

Intending that we change this nappy because of, and in accordance with, your intention that we change the nappy does not entail taking a practical attitude towards actions you will perform. (I may simply predict them.)

With this in mind, now Consider two ways of further specifying what happens in the case of walking in the Tarantino sense.

Way of Further Specifying 1: I know that, in part, because I am pointing the gun at you, you intend that we walk. I therefore engage in parallel planning concerning our walking. In this case, the gun makes available the information needed for parallel planning to be rational and successful. Despite the background of coercion, this is a case of shared agency.

Way of Further Specifying 2: As before, I know that, in part, because I am pointing the gun at you, you intend that we walk. But I treat that intention as merely a predictor of your actions: the fact that you have this intention is simply enables me to be confident that you will walk (another would be to a neural intervention).

Consequence: same structure of intentions and knowledge, difference with respect to shared agency.

On the view I’m offering, there are two ways to further specify what is involved in walking together in the Tarantino sense, and one involves shared agency in a deeper sense than the other. But despite this, the individuals in the two cases have much the same intentions and knowledge. The difference, on my view, is in how the intentions get into action.

This is a reason for thinking that Bratman does after all fail to give sufficient conditions for shared agency.

[It also implies that, on the Simple View Revised, an exercise of shared agency does not require having intentions or commitments whose fulfilment requires an exercise of shared agency. (*CHECK: Is this also a consequence of Bratman’s view; does the fulfilment of the intentions may not require that the connection condition obtains?)]

Recall Beatrice and Baldric who provided a counterexample to the view that Bratman’s conditions for shared intention can be used to give sufficient conditions for acting as one.

This is a bit delicate. I am supposing that Beatrice and Baldric are each making use of the fact that Beatrice intends J1 and of the fact that Baldric intends that J2, but that they are neglecting to make any use of the fact that J1=J2.

So the only difference is that Beatrice and Baldric happen to have same task, whereas Ayesha and Ahmed have different tasks. But neither Beatrice nor Baldric makes use of the fact that they have the same task.

Beatrice does rely on the fact Baldric intends that they J1, of course; but she does not rely on the fact that what Baldric intends is what she intends.

true? A&A make use of?
Ayesha intends J₁ ✓ ✓
Ahmed intends J₂ ✓ ✓
J₁=J₂ ✗ ✗

	true?	A&A make use of?
Ayesha intends J₁	✓	✓
Ahmed intends J₂	✓	✓
J₁=J₂	✗	✗

true? B&B make use of?
Beatrice intends J₁ ✓ ✓
Baldric intends J₂ ✓ ✓
J₁=J₂ ✓ ✗

	true?	B&B make use of?
Beatrice intends J₁	✓	✓
Baldric intends J₂	✓	✓
J₁=J₂	✓	✗

What prevented Beatrice and Baldric from acting as one was their failure to exploit the fact that what Beatrice intends is what Baldric intends.

But how could they have exploited this fact? Can the Revised Simple View help us here? I think it can.

What prevented Beatrice and Baldric from acting as one was their failure to exploit the fact that what Beatrice intends is what Baldric intends. But how could they have exploited this fact? \textbf{Parallel planning is the way in which agents characteristically exploit facts about sameness of intention}.

[... missing bit ...] This is why it's plausible that the Revised Simple View does not succumb to the counterexample with Beatrice and Baldric ...

To see that there really is no shared agency, contrast these two with Caitlin and Ciaran who engage in parallel planning for J1 ...

Here are Caitlin and Ciaran. Each makes a plan for all the actions, the actions the other will eventually perform as well as the actions she herself will perform.

So there is a sense in which they see their actions as having a kind of practical unity, and for this reason their case involves a joint action.

Now I want to return to that counterexample to Bratman. Earlier I said it’s a bit unclear whether there is a contrast with respect to shared agency. But now I think

This is a case where we have interconnected planning but no shared agency.

Joint Action

Parallel but Merely Individual Action

Caitlin & Ciaran’s making the cross hit the red square.

Beatrice & Baldric’s making the cross hit the red square

Two sisters cycling together.

Two strangers cycling the same route side-by-side.

Members of a flash mob simultaneously open their newspapers noisily.

Onlookers simultaneously open their newspapers noisily.

Simple View

Simple View Revised

... and

we engage in parallel planning;

for each of us, the intention that we, you and I, φ together leads to action via our contribution to the parallel planning

(where the intention, the planning and the action are all appropriately related).

So I claim that the notion of parallel planning unlike the notion of interconnected planning, gives us an account of shared agency which overcomes both counterexamples to the Simple View and counterexamples to Bratman’s view.

What happened to the notion of aggregate subject?

I’m still trying to construct them ...

How?

aggregate subject

Actually I think we have aggregate subjects. You don’t see them from the outside --- the Revised Simple View just describes individual agents as planning with the result that they have matching plans.

But you do see them from the inside: from the point of view of agents involved in parallel planning, they adopt the perspective of the aggregate subject. There are just actions; not mine or yours, just actions.

So I have ended up with a position quite different from Helm’s, or from Pettit and List’s (although my view is compatible with the important bits of their view) ...

... recall Helm:

On accounts like Bratman’s or Gilbert’s, ‘it makes some sense to say that the result is a kind of shared action: the individual people are, after all, acting intentionally throughout.

However, in a deeper sense, the activity is not shared: the group itself is not engaged in action whose aim the group finds worthwhile, and so the actions at issue here are merely those of individuals.

Thus, these accounts ... fail to make sense of a ... part of the landscape of social phenomena’

\citep[pp.~20--1]{helm_plural_2008}

Helm (2008, pp. 20-1)

How to make sense of this idea? Helm wants to make sense of it from the outside; I think this is a mistake and we have to make sense of it from the inside, that is, from the perspective of the individual agents themselves.

acting as one

I think the Revised Simple View captures a notion of acting as one. But let me be careful here because the phrase ‘acting as one’ could be misleading. What is as one?

From the point of view of the agents, it is not a matter of there being one agent or many agents. My suggesting is that practical deliberation and intention are, in the most basic cases, indifferent as between one and two agents acting. The question of who is acting can be left open at the start and is eventually settled by the world rather than by a decision on our part. There is nothing you need to add to intention to get shared intention.

So ‘as one’ does not refer to our being one. We aren't one and we aren't many because we aren't yet in the picture at all. Rather the suggestion is that acting as one is a matter of us conceiving of our actings as having a certain kind of unity.

conclusion

In conclusion, ...

Diagnosis

Too reflective!

Grounded merely on intuitive contrasts!

I think parallel planning addresses the first of the two obstacles we face.

Question

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

Finally we answered the question.

Simple View

Simple View Revised

... and

we engage in parallel planning;

for each of us, the intention that we, you and I, φ together leads to action via our contribution to the parallel planning

(where the intention, the planning and the action are all appropriately related).

So the Simple View Revised answers the question.

Except that there are some objections to the necessity of these conditions. Dealing with these will also force us to confront, finally our other problem ...

Diagnosis

Too reflective!

Grounded merely on intuitive contrasts!

I think parallel planning addresses the first of the two obstacles we face.

Keyboard Shortcuts?

Lecture 12

Joint Action

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Parallel Planning

The Simple View Revised

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