The Nash counterfactual considers the question: what would happen were I to change my behaviour assuming no one else does. By contrast, the Kantian counterfactual considers the question: what would happen were everyone to deviate from some behaviour. We present a model that endogenizes the decision to engage in this type of Kantian reasoning. Autonomous agents using this moral framework receive psychic payoffs equivalent to the cooperate-cooperate payoff in Prisoner’s Dilemma regardless of the other player’s action. Moreover, if both interacting (...) agents play Prisoner’s Dilemma using this moral framework, their material outcomes are a Pareto improvement over the Nash equilibrium. (shrink)

This entry addresses the question of group minds, by focusing specifically on empirical arguments for group cognition and group cognitive states. Two kinds of positive argument are presented and critically evaluated: the argument from individually unintended effects and the argument from functional similarity. A general argument against group cognition – which appeals to Occam’s razor – is also discussed. In the end, much turns on the identification of a mark of the cognitive; proposed marks are briefly surveyed in the final (...) section. (shrink)

We study shared intentions in what we call “loose groups”. These are groups that lack a codified organizational structure, and where the communication channels between group members are either unreliable or not completely open. We start by formulating two desiderata for shared intentions in such groups. We then argue that no existing account meets these two desiderata, because they assume either too strong or too weak an epistemic condition, that is, a condition on what the group members know and believe (...) about what the others intend, know, and believe. We propose an alternative, pooled knowledge, and argue that it allows formulating conditions on shared intentions that meet the two desiderata. (shrink)

The coordinated attack scenario and the electronic mail game are two paradoxes of common knowledge. In simple mathematical models of these scenarios, the agents represented by the models can coordinate only if they have common knowledge that they will. As a result, the models predict that the agents will not coordinate in situations where it would be rational to coordinate. I argue that we should resolve this conflict between the models and facts about what it would be rational to do (...) by rejecting common knowledge assumptions implicit in the models. I focus on the assumption that the agents have common knowledge that they are rational, and provide models to show that denying this assumption suffices for a resolution of the paradoxes. I describe how my resolution of the paradoxes fits into a general story about the relationship between rationality in situations involving a single agent and rationality in situations involving many agents. (shrink)

Shoemaker argues that one could not hold both that the qualitative character of colour experience is inherited from the qualitative character of the experienced colour and that there are faultless forms of variation in colour perception. In this paper, I explain what is meant by inheritance and discuss in detail the problematic cases of perceptual variation. In so doing I argue that these claims are in fact consistent, and that the appearance to the contrary is due to an optional and (...) controversial conception of experience that should be rejected. (shrink)

Strawson style counterexamples to Grice’s account of communication show that a communicative intention has to be overt. Saying what overtness consists in has proven to be difficult for Gricean accounts. In this paper, I show that a common explanation of overtness, one that construes it in terms of a network of shared beliefs or knowledge, is mistaken. I offer an alternative, collectivist, model of communication. This model takes the utterer’s communicative intention to be a we-intention, a kind of intention with (...) a distinctive content that cannot be reduced to an intention in favor of an individual action. I show that the collectivist model can explain overtness in terms of a general feature of we-intentions, namely the requirement that the participants in a shared activity are to intend to act in accordance with meshing subplans. (shrink)

In this paper, I advance a counterexample to the collective agency thesis.

Most reductionist accounts of intentional joint action include a condition that it must be common knowledge between participants that they have certain intentions and beliefs that cause and coordinate the joint action. However, this condition has typically simply been taken for granted rather than argued for. The condition is not necessary for ensuring that participants are jointly responsible for the action in which each participates, nor for ensuring that each treats the others as partners rather than as social tools. It (...) is thus something of a mystery why the condition is so widely accepted. By rejecting three arguments that could potentially support it, I argue that reductionists should get rid of the condition. I show that two of the arguments fail. While the third argument is intuitively compelling, it builds on key premises that are unavailable to the reductionist. (shrink)

An opinionated introduction to philosophical issues connected to common knowledge.

Sometimes individuals act together, and sometimes each acts on his or her own. It's a distinction that often matters to us. Undertaking a difficult task collectively can be comforting, even if only for the solidarity it may engender. Or, to take a very different case, the realization (or delusion) that the many bits of rudeness one has been suffering of late are part of a concerted effort can be of significance in identifying what one is up against: the accumulation of (...) grievances (no doubt well catalogued) is seen, not as an unfortunate coincidence of affronts stemming from various quarters, but as itself a product of a unified exercise of agency. A paranoid conspiracy theorist is not usually to be taken seriously. But he does get right that it certainly would be awful, for example, if everyone were out to get him and were working together to do so. After all, the stability and impact of agency that's shared can be expected to be more serious than the effects of a mere collection of individual acts.[1.. (shrink)

This is a survey article on reductive views of shared intention.

The notions 'worldview' and 'social identity' are examined to consider whether they contribute substantively to causal sequences or networks or thought clusters that result in group acts executed intentionally. ... Three proposed explanaitons of sectarian conflict or ethnic violence are analysed as examples of theories that causally link intenitonal group behaivour to the worldviews and social identities of the individual agents directly involved. But as will be shown, it is not a priori features of worldivews and identities as such, but (...) historically specific facts and contingent circumstances that need to be examined in order to explain group-motivated behaviour. Reference to worldviews and identities detract from adequate explanation. (shrink)