In the literature of collective intentions, the ‘we-intentions’ that lie behind cooperative actions are analysed in terms of individual mental states. The core forms of these analyses imply that all Nash equilibrium behaviour is the result of collective intentions, even though not all Nash equilibria are cooperative actions. Unsatisfactorily, the latter cases have to be excluded either by stipulation or by the addition of further, problematic conditions. We contend that the cooperative aspect of collective intentions is not a property of (...) the intentions themselves, but of the mode of reasoning by which they are formed. We analyse collective intentions as the outcome of team reasoning, a mode of practical reasoning used by individuals as members of groups. We describe this mode of reasoning in terms of formal schemata, discuss a range of possible accounts of group agency, and show how existing theories of collective intentions fit into this framework. (shrink)

_ Convention_ was immediately recognized as a major contribution to the subject and its significance has remained undiminished since its first publication in 1969. Lewis analyzes social conventions as regularities in the resolution of recurring coordination problems-situations characterized by interdependent decision processes in which common interests are at stake. Conventions are contrasted with other kinds of regularity, and conventions governing systems of communication are given special attention.

Current debates in social ontology are dominated by approaches that view institutions either as rules or as equilibria of strategic games. We argue that these two approaches can be unified within an encompassing theory based on the notion of correlated equilibrium. We show that in a correlated equilibrium each player follows a regulative rule of the form ‘if X then do Y’. We then criticize Searle's claim that constitutive rules of the form ‘X counts as Y in C’ are fundamental (...) building blocks for institutions, showing that such rules can be derived from regulative rules by introducing new institutional terms. Institutional terms are introduced for economy of thought, but are not necessary for the creation of social reality. (shrink)

The Philosophy of Sociality offers new ideas and conceptual tools for philosophers and social scientists in their analysis of the social world.

I discuss how simulating another agent can be useful in some game-theoretical situations, particularly iterated games such as the centipede game.

We explore the idea that a group or ‘team’ of individuals can be an agent in its own right and that, when this is the case, individual team members use team reasoning, a distinctive mode of reasoning from that of standard decision theory. Our approach is to represent team reasoning explicitly, by means of schemata of practical reasoning in which conclusions about what actions should be taken are inferred from premises about the decision environment and about what agents are seeking (...) to achieve. We use this theoretical framework to compare team reasoning with the individual reasoning of standard decision theory, and to compare various theories of team agency and collective intentionality. (shrink)

It is advisable to treat some sorts of discourse about fiction with the aid of an intensional operator "in such-And-Such fiction...." the operator may appear either explicitly or tacitly. It may be analyzed in terms of similarity of worlds, As follows: "in the fiction f, A" means that a is true in those of the worlds where f is told as known fact rather than fiction that differ least from our world, Or from the belief worlds of the community in (...) which the fiction originated. (shrink)

Understanding Institutions proposes a new unified theory of social institutions that combines the best insights of philosophers and social scientists who have written on this topic. Francesco Guala presents a theory that combines the features of three influential views of institutions: as equilibria of strategic games, as regulative rules, and as constitutive rules. -/- Guala explains key institutions like money, private property, and marriage, and develops a much-needed unification of equilibrium- and rules-based approaches. Although he uses game theory concepts, the (...) theory is presented in a simple, clear style that is accessible to a wide audience of scholars working in different fields. Outlining and discussing various implications of the unified theory, Guala addresses venerable issues such as reflexivity, realism, Verstehen, and fallibilism in the social sciences. He also critically analyses the theory of “looping effects” and “interactive kinds” defended by Ian Hacking, and asks whether it is possible to draw a demarcation between social and natural science using the criteria of causal and ontological dependence. Focusing on current debates about the definition of marriage, Guala shows how these abstract philosophical issues have important practical and political consequences. -/- Moving beyond specific cases to general models and principles, Understanding Institutions offers new perspectives on what institutions are, how they work, and what they can do for us. (shrink)

This work provides a rigorous analysis of what Tuomela calls ‘the we-perspective’. Tuomela's overarching project is to argue that ‘conceptualizing social life and theorizing about it requires the use of group concepts, indeed the we-perspective and, especially, the we-mode.’ Already some of the complexities of Tuomela's approach will be evident – viz. in the distinction, implied in the above quotation and carried through systematically throughout the work, between the ‘we-perspective’ and the ‘we-mode’. For, indeed, it is possible, on his account, (...) to take up the we-perspective from the I-mode and, indeed, this is probably quite common, but is not adequate to ground the analysis of social and institutional concepts. As Tuomela puts it, ‘The concept of social institution is a we-mode concept, and in actual practice, at least some we-mode thinking and acting is required for institutions to function adequately.’ Since ‘we-mode’ is the more central notion, let us begin with that. It will be instructive to quote Tuomela at length : " Agent A, a member of group g, has ATT, the attitude ATT with content p, in … ". (shrink)

Game theory is central to modern understandings of how people deal with problems of coordination and cooperation. Yet, ironically, it cannot give a straightforward explanation of some of the simplest forms of human coordination and cooperation--most famously, that people can use the apparently arbitrary features of "focal points" to solve coordination problems, and that people sometimes cooperate in "prisoner's dilemmas." Addressing a wide readership of economists, sociologists, psychologists, and philosophers, Michael Bacharach here proposes a revision of game theory that resolves (...) these long-standing problems. In the classical tradition of game theory, Bacharach models human beings as rational actors, but he revises the standard definition of rationality to incorporate two major new ideas. He enlarges the model of a game so that it includes the ways agents describe to themselves their decision problems. And he allows the possibility that people reason as members of groups, each taking herself to have reason to perform her component of the combination of actions that best achieves the group's common goal. Bacharach shows that certain tendencies for individuals to engage in team reasoning are consistent with recent findings in social psychology and evolutionary biology. As the culmination of Bacharach's long-standing program of pathbreaking work on the foundations of game theory, this book has been eagerly awaited. Following Bacharach's premature death, Natalie Gold and Robert Sugden edited the unfinished work and added two substantial chapters that allow the book to be read as a coherent whole. (shrink)

Do conventions need to be common knowledge in order to work? David Lewis builds this requirement into his definition of a convention. This paper explores the extent to which his approach finds support in the game theory literature. The knowledge formalism developed by Robert Aumann and others militates against Lewis’s approach, because it shows that it is almost impossible for something to become common knowledge in a large society. On the other hand, Ariel Rubinstein’s Email Game suggests that coordinated action (...) is no less hard for rational players without a common knowledge requirement. But an unnecessary simplifying assumption in the Email Game turns out to be doing all the work, and the current paper concludes that common knowledge is better excluded from a definition of the conventions that we use to regulate our daily lives. (shrink)

John Searle began to discuss his recently published book `The Construction of Social Reality' with Anthony Freeman, and they ended up talking about God. The book itself and part of their conversation are introduced and briefly reflected upon by Anthony Freeman. Many familiar social facts -- like money and marriage and monarchy -- are only facts by human agreement. They exist only because we believe them to exist. That is the thesis, at once startling yet obvious, that philosopher John Searle (...) explores in The Construction of Social Reality. (shrink)

Page 1. Economics and Philosophy, 26 291--320 Copyright C Cambridge University Press doi: 10.1017 / S0266267110000386 TWO KINDS OF WE-REASONING RAUL HAKLI, KAARLO MILLER AND RAIMO TUOMELA University of Helsinki.