Game theory is the systematic study of interdependent rational choice. It should be distinguished from decision theory, the systematic study of individual (practical and epistemic) choice in parametric contexts (i.e., where the agent is choosing or deliberating independently of other agents). Decision theory has several applications to ethics (see Dreier 2004; Mele and Rawlings 2004). Game theory may be used to explain, to predict, and to evaluate human behavior in contexts where the outcome of action depends on what several agents (...) choose to do and where their choices depend on what others choose to do. (See the entry on game theory) Game theory consequently is relevant to ethics, and it is used in moral and political philosophy in a variety of ways. We shall concentrate on the influence and use of game theory in ethics and those parts of political theory involving norms or principles of justice, ignoring questions about political and legal institutions on the one hand and questions about issues dealing with moral virtues on the other. (shrink)

The chapter reviews recent theoretical and empirical developments concerning the theory of team reasoning in game theoretic interactions.

Politics, Philosophy & Economics, Volume 21, Issue 4, Page 347-371, November 2022. We sometimes have to choose between options that are seemingly incomparable insofar as they seem to be neither better than, worse than, nor equal to each other. This often happens when the available options are quite different from one another. For instance, consider a choice between prioritizing either criminal justice reform or healthcare reform as a public policy goal. Even after the relevant details of the goals and possible (...) reforms are filled in, it is plausible that neither goal is better than, worse than, nor equal to the other. Such seemingly incomparable options present a problem for rational choice since it is unclear how an agent might rationally choose between them. What we need are some principles to help govern rational choice when faced with seemingly incomparable options. I here present three such principles. While each principle is individually compelling, I show that they are jointly incompatible. I then argue that the correct response to this inconsistent triad is to reject the principle that rationally censures performing a sequence of choices one knows will result in a suboptimal outcome. The upshot is that when seeming incomparability is involved, an agent can money pump themselves without being less rational for it. (shrink)

Against the orthodox view of the Nash equilibrium as “the embodiment of the idea that economic agents are rational” (Aumann, 1985, p 43), some theorists have proposed ‘non-classical’ concepts of rationality in games, arguing that rational agents should be capable of improving upon inefficient equilibrium outcomes. This paper considers some implications of these proposals for economic theory, by focusing on institutional design. I argue that revisionist concepts of rationality conflict with the constraint that institutions should be designed to be incentive-compatible, (...) that is, that they should implement social goals in equilibrium. To resolve this conflict, proponents of revisionist concepts face a choice between three options: (1) reject incentive compatibility as a general constraint, (2) deny that individuals interacting through the designed institutions are rational, or (3) accept that their concepts do not cover institutional design. I critically discuss these options and I argue that a more inclusive concept of rationality, e.g. the one provided by Robert Sugden’s version of team reasoning, holds the most promise for the non-classical project, yielding a novel argument for incentive compatibility as a general constraint. (shrink)

This paper considers contractarianism as a method of justification. The analysis accepts the key tenets of contractarianism: expected utility maximization, unanimity as the criteria of acceptance, and social-scientific uncertainty of modelled agents. In addition to these three features, however, the analysis introduces a fourth feature: a criteria of rational belief formation, viz. Bayesian belief updating. Using a formal model, this paper identifies a decisive objection to contractarian justification. Insofar as contractarian projects approximate the Agreement Model, therefore, they fail to justify (...) their conclusions. Insofar as they fail to approximate the Agreement Model, they must explain which modelling assumption they reject. (shrink)

In a 2013 article, David Gauthier noted upon the twenty-fifth anniversary of the publication of Morals by Agreement that his contractarian approach to morality had found a niche among ‘some of those who remain unpersuaded by either Kantianism or utilitarianism’. In this article I will focus on Pareto optimization and I will argue that the Gauthier contract, even in spite of the article’s revisions, is still less useful for consultation purposes than Gauthier is assuming. To highlight the conceptual distance that (...) I think separates the Gauthier contract from real-world circumstances—a separation that is greater than Gauthier supposes—I will focus on the problem of ‘civic defection’. The point is not for us to repudiate as such the deliverances of the Gauthier model, but simply to use caution in our deployment of the model, and, in order to access the full extent of the model’s offerings, to resist the temptation to deploy it in the service of purposes which it is not capable of accomplishing. (shrink)

David Gauthier a dit un jour que le contrat social constitue la seule option permettant de parvenir à une morale rationnelle. Je soutiens qu’il a raison. La morale se compose de règles notionnelles visant tout le monde, partout. Seuls les individus sont rationnels, et ils ont des intérêts divers. Le contrat social propose des principes auxquels chacun, compte tenu de sa situation sociale et environnementale, consent bien qu’ils limitent les activités par lesquelles chacun poursuit ses buts. Il n’existe aucun autre (...) moyen rationnel de comprendre la morale; c’est donc bien la seule option possible. (shrink)

Abstract. In Minimal Morality (2018), I develop a multilevel social contract theory that accommodates deep moral pluralism. In this article, I reply to comments by Gaus, Van Schoelandt and Cooper concerning the three core projects of the book that aim to (i) revive orthodox rational choice contractarianism as a viable approach to the social contract, (ii) integrate this approach into a comprehensive social contract theory and (iii) show the applicability of the theory to the real world. My replies clarify some (...) of the main features of the theory, defend its core projects and expand discussion of some of its details in order to show that the theory can address the challenges raised. (shrink)

In a recent article, Gauthier rejects orthodox rational choice contractarianism in favor of a revisionist approach to the social contract that, according to him, justifies his principle of maximin proportionate gain as a principle of distributive justice. I agree with Gauthier that his principle of maximin proportionate gain cannot be justified by orthodox rational choice contractarianism. I argue, however, that orthodox rational choice contractarianism, before and after Gauthier, is still a viable approach to the social contract, although the scope of (...) this approach is limited. Orthodox rational choice contractarianism can be applied fruitfully to moral philosophy only in situations of deep moral pluralism in which moral reasoning is reduced to instrumental reasoning, because the members of society do not share, as assumed by traditional moral theories, a consensus on moral ideals as traditionally conceived as a starting point for the derivation of moral rules but only an overarching end that they aim to reach. If orthodox rational choice contractarianism is applied adequately, then it offers a viable approach to the social contract that, in contrast to Gauthier’s theory, justifies a rival principle for distributive conflicts that is valid for deeply morally pluralistic societies. (shrink)

In a recent article, McClennen (2012) defends an alternative bargaining theory in response to his criticisms of the standard Nash bargaining solution as a principle of distributive justice in the context of the social contract. McClennen rejects the orthodox concept of expected individual utility maximizing behavior that underlies the Nash bargaining model in favor of what he calls full rationality, and McClennen’s full cooperation bargaining theory demands that agents select the most egalitarian strictly Pareto-optimal distributional outcome that is strictly Pareto-superior (...) to the state of nature. I argue that McClennen’s full cooperators are best described as reasonable agents whose rationality is constrained by moral considerations and that McClennen’s bargaining theory is moralized in this regard. If, by contrast, the orthodox concept of rationality is assumed and plausible assumptions are made about human nature and social cooperation, then a modified version of the standard Nash bargaining solution, which I call the stabilized Nash bargaining solution (Moehler 2010), is justified. From the perspective of rational agents, the stabilized Nash bargaining solution can accommodate McClennen’s criticisms of the standard Nash bargaining solution in the context of the social contract and, for such agents, it can serve as a principle of distributive justice in deeply morally pluralistic societies. (shrink)

The history of contractarian moral theory is long and varied. It includes the classic social contract theories of Hobbes (1651), Hume (1739/1740), and Kant (1785) as well as modern versions of these theories, such as those of Gauthier (1986), Scanlon (1998), Darwall (2006), and Southwood (2010). In Minimal Morality: A Multilevel Social Contract Theory (2018), I continue this tradition by developing a ‘multilevel social contract theory’ that combines Humean, Hobbesian, and Kantian moral features. In this article, I reply to comments (...) by Fred D’Agostino, John Thrasher, Christopher W. Morris, and Peter Vanderschraaf. I am deeply grateful for these commentators’ constructive and engaging comments that, in their own way, shed light on core assumptions and features of the theory. Due to space restrictions, I focus on what I consider to be the main criticisms and have organized my responses thematically. I hope that doing so will also help readers who are less familiar with my work to understand the relevance of multilevel social contract theory for morally diverse societies. (shrink)

The game theoretic notion of best-response reasoning is sometimes criticized when its application produces multiple solutions of games, some of which seem less compelling than others. The recent development of the theory of team reasoning addresses this by suggesting that interacting players in games may sometimes reason as members of a team – a group of individuals who act together in the attainment of some common goal. A number of properties have been suggested for team-reasoning decision-makers’ goals to satisfy, but (...) a few formal representations have been discussed. In this paper we suggest a possible representation of these goals based on the notion of mutual advantage. We propose a method for measuring extents of individual and mutual advantage to the interacting decision-makers, and define team interests as the attainment of outcomes associated with maximum mutual advantage in the games they play. (shrink)

Standard game theory cannot explain the selection of payoff-dominant outcomes that are best for all players in common-interest games. Theories of team reasoning can explain why such mutualistic cooperation is rational. They propose that teams can be agents and that individuals in teams can adopt a distinctive mode of reasoning that enables them to do their part in achieving Pareto-dominant outcomes. We show that it can be rational to play payoff-dominant outcomes, given that an agent group identifies. We compare team (...) reasoning to other theories that have been proposed to explain how people can achieve payoff-dominant outcomes, especially with respect to rationality. Some authors have hoped that it would be possible to develop an argument that it is rational to group identify. We identify some large—probably insuperable—problems with this project and sketch some more promising approaches, whereby the normativity of group identification rests on morality. (shrink)

Sometimes we make a decision about an action we will undertake later and form an intention, but our judgment of what it is best to do undergoes a temporary shift when the time for action comes round. What makes it rational not to give in to temptation? Many contemporary solutions privilege diachronic rationality; in some “rational non-reconsideration” (RNR) accounts once the agent forms an intention, it is rational not to reconsider. This leads to other puzzles: how can someone be motivated (...) to follow a plan that is contrary to their current judgment? How can it be rational to form a plan to resist if we can predict that our judgment will shift? I show how these puzzles can be solved in a framework where there are multiple units of agency, distinguishing between the judgments of the timeslice and those of the person over time, and allowing that the timeslice can “self identify”, taking the person over time as the relevant unit of agency and doing intrapersonal team reasoning (with a different causal role for intentions than RNR accounts). On my account, resisting temptation is compatible with synchronic rationality, so synchronic and diachronic rationality are aligned. However, either resisting or succumbing to temptation can be instrumentally rational, depending on the unit of agency that is identified with. In order to show why we ought to resist temptation, we need to draw on a non-instrumental rationale. I sketch possible routes for doing this. (shrink)

This essay examines two different modes of reasoning about justice: an individual mode in which each individual judges what we all ought to do and a social mode in which we seek to reconcile our judgments of justice so that we can share common rules of justice. Social contract theory has traditionally emphasized the second, reconciliation mode, devising a central plan to do so. However, I argue that because we disagree not only in our judgments of justice but also about (...) the degree of reconciliation justice calls for, the social contract presupposes a single, controversial, answer to the proper degree of reconciliation. In place of the social contract’s ‘top-down’ approach, this article explores the idea of self-organizing moral systems, in which each individual, acting on her own views of justice, responds to the decisions of others, forming systems of shared justice. Several basic agent-based models are explored to begin to understand the dynami... (shrink)

:Team reasoning is thought to be descriptively and normatively superior to the classical individualistic theory of rational choice primarily because it can recommend coordination on Hi in the Hi-Lo game and cooperation in Prisoner's Dilemma-type situations. However, left unanswered is whether it is rational for individuals to become team members, leaving a gap between reasons for individuals and reasons for team members. In what follows, I take up Susan Hurley's attempt to show that it is rational for an individual to (...) become a team member. I argue that her account fails to show that becoming a team member is necessary to gain the advantages of coordination in Hi-Lo games or cooperation in Prisoner's Dilemma-type situations, and that individuals will often fare better reasoning as individual agents than as members of a team. I argue further that there is a more general problem for team reasoning, specifically that the conditions needed to make it rational for a team member to employ team reasoning make becoming a team member unnecessary. (shrink)

This paper takes up David Gauthier's most recent defense of the rationality of cooperation in prisoner's dilemmas. In that defense, Gauthier argues for a Pareto-optimizing theory of rational choice. According to Gauthier, rational action should sometimes aim at Pareto-optimization, and cooperation in prisoner's dilemmas is rational because it is Pareto-optimizing. I argue that Pareto-optimization cannot justify cooperation in the prisoner's dilemma in a manner that is also consistent with Gauthier's other desiderata. Either: the rationality of cooperation must derive from what (...) is beneficial for the group rather than what is beneficial for the individual, leaving the individual qua individual without any reason to cooperate, or Gauthier cannot explain why defecting in prisoner's dilemmas is not also rational. (shrink)

This paper proposes a new interpretation of non-cooperative games that shows why the unilateralism of best-reply reasoning fails to capture the mutuality of strategic interdependence. Drawing on an intersubjective approach to theorizing individual agency in shared context, including a non-individualistic model of common belief without infinite regress, the paper develops a general model of a 2 × 2 simultaneous one-shot non-cooperative game and applies it to games including Hi-Lo, Stag Hunt, Prisoners’ Dilemma, Chicken, BoS and Matching Pennies. Results include High (...) as the rational choice in Hi-Lo, and Cooperate as a possible rational choice in the Prisoners’ Dilemma. (shrink)

I focus on David Gauthier’s intriguing suggestion that actions are not to be evaluated directly but via an evaluation of deliberative procedures. I argue that this suggestion is misleading, since even the most direct evaluation of (intentional) actions involves the evaluation of different ways of deliberating about what to do. Relatedly, a complete picture of what an agent is or might be (intentionally) doing cannot be disentangled from a complete picture of how s/he is or might be deliberating. A more (...) viable contrast concerns whether actions and deliberative procedures are properly evaluated on the whole or, instead, through time. (shrink)

We share our world with many people who ignore the principles of justice and who regularly take advantage of others by breaching trust or breaking agreements. This dissertation is about the irrationality of the actions of these covenant-breakers. A covenant-breaker typically believes that unjust behavior is to his advantage and that only a fool would act in any other way. Would it not be disturbing if this were true? My central claim will be that adherence to the precepts of justice (...) is a rational strategy for a self-interested actor. I intend to demonstrate that con men and covenant-breakers do not act rationally when violating an agreement. I will trace the concept of justice as it evolves through philosophical history and show that, while the concept of justice changes as the underlying concept of human nature and psychology changes, the argument in favor of the rationality of just behavior remains coherent throughout. Each historical interpretation will advance some form of the claim that the consistent observance of cooperative agreements is a rational strategy, and at each point an interlocutor will object. I will show that these interlocutors are mistaken. My motivating goal is to show that justice, understood as the consistent observance of cooperative agreements, is rational. I want to respond to the clandestine cheaters and other skeptics who believe that just behavior is for suckers, because, if the skeptics are right, and justice is indeed irrational, then those among us who are acting in a just manner are paying an unnecessary cost. (shrink)

Moral error theorists argue that moral thought and discourse are systematically in error, and that nothing is, or can ever be, morally permissible, required or forbidden. I begin by discussing how error theorists arrive at this conclusion. I then argue that if we accept a moral error theory, we cannot escape a pressing problem – what should we do next, metaethically speaking? I call this problem the ‘what now?’ problem, or WNP for short. I discuss the attempts others have made (...) to respond to the WNP, and in each case I show that the responses fail to be satisfying. I then propose a new response to the WNP, which I call revolutionary relativism. I define revolutionary relativism, explain why it is preferable to the existing responses to the WNP, and defend it against the most problematic objections I anticipate that opponents might raise. I conclude that revolutionary relativism succeeds where previous WNP responses fail, and that if we accept a moral error theory, we should become revolutionary relativists. (shrink)

One of the conceptual limitations of the orthodox game theory is its inability to offer definitive theoretical predictions concerning the outcomes of noncooperative games with multiple rationalizable outcomes. This prompted the emergence of goal-directed theories of reasoning – the team reasoning theory and the theory of hypothetical bargaining. Both theories suggest that people resolve non-cooperative games by using a reasoning algorithm which allows them to identify mutually advantageous solutions of non-cooperative games. The primary aim of this thesis is to enrich (...) the current debate on goaldirected reasoning theories by studying the extent to which the principles of the bargaining theory can be used to formally characterize the concept of mutual advantage in a way which is compatible with some of the conceptually compelling principles of orthodox game theory, such as individual rationality, incentive compatibility, and non-comparability of decision-makers’ personal payoffs. I discuss two formal characterizations of the concept of mutual advantage derived from the aforementioned goal-directed reasoning theories: A measure of mutual advantage developed in collaboration with Jurgis Karpus, which is broadly in line with the notion of mutual advantage suggested by Sugden, and the benefit-equilibrating bargaining solution function, which is broadly in line with the principles underlying Conley and Wilkie’s solution for Pareto optimal point selection problems with finite choice sets. I discuss the formal properties of each solution, as well as its theoretical predictions in a number of games. I also explore each solution concept’s compatibility with orthodox game theory. I also discuss the limitations of the aforementioned goal-directed reasoning theories. I argue that each theory offers a compelling explanation of how a certain type of decision-maker identifies the mutually advantageous solutions of non-cooperative games, but neither of them offers a definitive answer to the question of how people coordinate their actions in non-cooperative social interactions. (shrink)