Practical reason or rationality can be understood in agent‐based terms. Strength of purpose, for example, can be internally characterized, and the rationality of the courage to face facts and not deceive oneself about what is unpleasant or horrifying can also be understood in agent‐based terms. Practical rationality also requires us not to be self‐defeatingly insatiable in our wants, but this likewise is a feature of inner motivation. Finally, being rational seems to require a certain amount of (...) concern for one's own well‐being or happiness – just as being moral requires a certain kind of concern for others; but like the other conditions of practical rationality just mentioned, this kind of concern can readily be understood in agent‐based terms. In fact, it makes more intuitive sense to understand the rationality of self‐interest in terms of motivation than to understand it in terms of consequences. (shrink)

Agent-based accounts of virtue ethics, such as the one provided by Michael Slote, base the rightness of action in the motive from which it proceeds. A frequent objection to agent-basing is that it does not allow us to draw the commonsense distinction between doing the right thing and doing it for the right reasons, that is, between act-evaluation and agent-appraisal. I defend agent-basing against this objection, but argue that a more fundamental problem for this account (...) is its apparent failure to provide adequate argue action guidance. I then show that this problem can be solved by supplementing an agent-based criterion of right action with a hypothetical-agent criterion of action guidance. (shrink)

In this paper, we present an agent-based model for studying the impact of 'myside bias' on the argumentative dynamics in scientific communities. Recent insights in cognitive science suggest that scientific reasoning is influenced by `myside bias'. This bias manifests as a tendency to prioritize the search and generation of arguments that support one's views rather than arguments that undermine them. Additionally, individuals tend to apply more critical scrutiny to opposing stances than to their own. Although myside bias (...) may pull individual scientists away from the truth, its effects on communities of reasoners remain unclear. The aim of our model is two-fold: first, to study the argumentative dynamics generated by myside bias, and second, to explore which mechanisms may act as a mitigating factor against its pernicious effects. Our results indicate that biased communities are epistemically less successful than non-biased ones, and that they also tend to be less polarized than non-biased ones. Moreover, we find that two socio-epistemic mechanisms help communities to mitigate the effect of the bias: the presence of a common filter on weak arguments, which can be interpreted as shared beliefs, and an equal distribution of agents for each alternative at the beginning. (shrink)

In this contribution we propose an agent architecture for theorem proving which we intend to investigate in depth in the future. The work reported in this paper is in an early state, and by no means finished. We present and discuss our proposal in order to get feedback from the Calculemus community.

This book provides an argumentation model for means-end reasoning, a distinctive type of reasoning used for problem-solving gand decision-making. Means-end reasoning is modeled as goal-directed argumentation from an agent's goals and known circumstances, and from an action selected as a means, to a decision to carry out the action. Goal-based reasoning for argumentation provides an argumentation model for this kind of reasoning, showing how it is employed in settings of intelligent deliberation where agents (...) try to collectively arrive at a conclusion on what they should do to move forward in a set of circumstances. The book explains how this argumentation model can help build more realistic computational systems of deliberation and decision-making and shows how such systems can be applied to solve problems posed by goal-based reasoning in numerous fields, from social psychology and sociology, to law, political science, anthropology, cognitive science, artificial intelligence, multi-agent systems, and robotics." -- Back cover. (shrink)

Abstract Agent-based virtue ethics is a unitary normative theory according to which the moral status of actions is entirely dependent upon the moral status of an agent's motives and character traits. One of the problems any such approach faces is to capture the common-sense distinction between an agent's doing the right thing, and her doing it for the right (or wrong) reason. In this paper I argue that agent-based virtue ethics ultimately fails to capture (...) this kind of fine-grained distinction, and to this extent ought to be rejected. I focus first on Michael Slote's agent-based theory, according to which the moral status of actions depends upon an agent's actual motives, and argue that this leads to a paradox. I then consider whether the ?counterfactual? version of agent-basing favoured by Rosalind Hursthouse and Linda Zagzebski fares any better, and conclude that it does not. (shrink)

Group-based reasons are reasons to play one’s part in some pattern of action that the members of some group could perform, because of the good features of the pattern. This paper discusses three broad conceptions of such reasons. According to the agency-first conception, there are no group-based reasons in cases where the relevant group is not or would not be itself an agent. According to the behaviour-first conception, what matters is that the other members of the group (...) would play their parts in the relevant pattern, not whether they would have the cooperative intentional states constitutive of group agency in doing so. This paper argues against these conceptions and in favour of the powers-first conception, according to which what matters is that the members of the group have practically relevant powers. (shrink)

Agent-based virtue ethical theories must deal with the problem of right action: if an action is right just in case it expresses a virtuous motive, then how can an agent perform the right action but for the wrong reason, or from a vicious motive? Some recent agent-based accounts purport to answer this challenge and two other related problems. Here I assess these accounts and show them to be inadequate answers to the problem of right action. (...) Overall, it is shown that the most recent and promising attempts at squaring agent-based virtue ethics with commonsense morality are flawed, and so, the case for agent-basing in general that much dimmer. (shrink)

In Morals From Motives, Michael Slote defends an agent-based theory of right action according to which right acts are those that express virtuous motives like benevolence or care. Critics have claimed that Slote’s view— and agent-based views more generally— cannot account for several basic tenets of commonsense morality. In particular, the critics maintain that agent-based theories: (i) violate the deontic axiom that ought implies can , (ii) cannot allow for a person’s doing the right (...) thing for the wrong reason, and (iii) do not yield clear verdicts in a number of cases involving conflicting motives and motivational over-determination . In this paper I develop a new agent-based theory of right action designed to avoid the problems presented for Slote’s view. This view makes morally right action a matter of expressing an optimal balance of virtue over vice and commands agents in each situation to improve their degree of excellence to the greatest extent possible. (shrink)

Agent-based models derive the behavior of artificial socio-economic entities computationally from the actions of a large number of agents. One objection is that highly idealized ABMs fail to represent the real world in any reasonable sense. Another objection is that they at best show how observed patterns may have come about, because simulations are easy to produce and there is no evidence that this is really what happens. Moreover, different models may well yield the same result. I will (...) rebut these objections by focusing on an often neglected, but crucial function of ABMs. Building on Gelfert’s account of the exploratory uses of scientific models I show that, in the absence of an accepted underlying theory, successful ABMs lend inductive support to assumptions concerning certain structural feutures of the behavioral rules employed. One core step towards this goal is what I call multiple-model robustness analysis. (shrink)

In ‘Against agent-based virtue ethics' (2004) Michael Brady rejects agent-based virtue ethics on the grounds that it fails to capture the commonsense distinction between an agent's doing the right thing, and her doing it for the right reason. In his view, the failure to account for this distinction has paradoxical results, making it unable to explain why an agent has a duty to perform a given action. I argue that Brady's objection relies on the (...) assumption that an agent-based account is committed to defining obligations in terms of actual motives. If we reject this view, and instead provide a version of agent-basing that determines obligations in terms of the motives of the hypothetical virtuous agent, the paradox disappears. (shrink)

Public reason liberalism includes an ideal of political stability where justified institutions reach a kind of self-enforcing equilibrium. Such an order must be stable for the right reasons — where persons comply with the rules of the order for moral reasons, rather than out of fear or self-interest. John Rawls called a society stable in this way well-ordered. In this essay, I contend that a more sophisticated model of a well-ordered society, specifically an agent-based model, yields a richer (...) and more attractive understanding of political stability. An agent-based model helps us to distinguish between three concepts of political stability — durability, balance, and immunity. A well-ordered society is one that possesses a high degree of social trust and cooperative behavior among its citizens (durability) with low short-run variability (balance). A well-ordered society also resists destabilization caused by noncompliant agents in or entering the system (immunity). Distinguishing between these three concepts complicates the necessary reformulation of the idea of a well-ordered society. Going forward, public reason theorists must now distinguish between types of assurance, specify heretofore unknown aspects of reasonable behavior, and reconceive of the nonideal preconditions for forming a stable, ideal social order. (shrink)

This paper argues against the priority of pure, virtue-based accounts of argumentative norms [VA]. Such accounts are agent-based and committed to the priority thesis: good arguments and arguing well are explained in terms of some prior notion of the virtuous arguer arguing virtuously. Two problems with the priority thesis are identified. First, the definitional problem: virtuous arguers arguing virtuously are neither sufficient nor necessary for good arguments. Second, the priority problem: the goodness of arguments is not explained (...) virtuistically. Instead, being excellences, virtues are instrumental in relation to other, non-aretaic goods—in this case, reason and rationality. Virtues neither constitute reasons nor explain their goodness. Two options remain for VA: either provide some account of reason and rationality in virtuistic terms, or accept them as given but non-aretaic goods. The latter option, though more viable, demands the concession that VA cannot provide the core norms of argumentation theory. (shrink)

There is an increasing need for norms to be embedded in technology as the widespread deployment of applications such as autonomous driving, warfare and big data analysis for crime fighting and counter-terrorism becomes ever closer. Current approaches to norms in multi-agent systems tend either to simply make prohibited actions unavailable, or to provide a set of rules which the agent is obliged to follow, either as part of its design or to avoid sanctions and punishments. In this paper (...) we argue for the position that agents should be equipped with the ability to reason about a system’s norms, by reasoning about the social and moral values that norms are designed to serve; that is, perform the sort of moral reasoning we expect of humans. In particular we highlight the need for such reasoning when circumstances are such that the rules should arguably be broken, so that the reasoning can guide agents in deciding whether to comply with the norms and, if violation is desirable, how best to violate them. One approach to enabling this is to make use of an argumentation scheme based on values and designed for practical reasoning: arguments for and against actions are generated using this scheme and agents choose between actions based on their preferences over these values. Moral reasoning then requires that agents have an acceptable set of values and an acceptable ordering on their values. We first discuss how this approach can be used to think about and justify norms in general, and then discuss how this reasoning can be used to think about when norms should be violated, and the form this violation should take. We illustrate how value based reasoning can be used to decide when and how to violate a norm using a road traffic example. We also briefly consider what makes an ordering on values acceptable, and how such an ordering might be determined. (shrink)

Models of content-sharing behavior on online social media platforms typically represent content spread as a diffusion process modeled on contagious diseases; users’ behavior is modeled with single-agent decision theory. However, social media platforms are interactive spaces where users care about reactions to, and further spread of, the content they post. Thus, social media interaction falls under the intended use cases for game theory. In contrast to existing models leaving strategic reasoning out, we capture agents’ social media decisions within (...) a cognitive hierarchy framework, which can be interpreted as making formally precise how agents make strategic choices based on mutual expectations of rationality. Analytically, we identify limit cases in which a platform can be swamped with content that no agents personally like but all expect to elicit reactions (think obvious fake-news). We then use agent-based simulations to show that a range of more realistic cases give rise to similar outcomes. (shrink)

Why do agent-relative reasons have authority over us, reflective creatures? Reductive accounts base the normativity of agent-relative reasons on agent-neutral considerations like ‘having parents caring especially for their own children serves best the interests of all children’. Such accounts, however, beg the question about the source of normativity of agent-relative ways of reason-giving. In this paper, I argue for a non-reductive account of the reflective necessity of agent-relative concerns. Such an account will reveal an important (...) structural complexity of practical reasoning in general. Christine Korsgaard relates the rational binding force of practical reasons to the various identities or self-conceptions under which we value ourselves. The problem is that it is not clear why such self-conceptions would necessitate us rationally, given the fact that most of our identities are simply given. Perhaps, Harry Frankfurt is right in arguing that we are not only necessitated by reason, but also, and predominantly by what we love. I argue, however, that “the necessities of love” (in Frankfurt’s phrase) are not to be separated from, but should be seen as belonging to the necessities of reason. Our loves, concerns and related identities provide for a specific and important structure to practical reflection. They function on the background of reasoning, having a specific default role: they would lose their character as concerns, if there was a need for them to be cited on the foreground of deliberation or if there was a need to justify them. This does not mean that our deep concerns cannot be scrutinised. They can only be scrutinised in an indirect way, however, which explains their role in grounding the normativity of agent-relative reasons. It appears that this account can provide for a viable interpretation of Korsgaard’s argument about the foundational role of practical identities. (shrink)

In this paper we apply a general account of practical reasoning to arguing about legal cases. In particular, we provide a reconstruction of the reasoning of the majority and dissenting opinions for a particular well-known case from property law. This is done through the use of Belief-Desire-Intention (BDI) agents to replicate the contrasting views involved in the actual decision. This reconstruction suggests that the reasoning involved can be separated into three distinct levels: factual and normative levels and (...) a level connecting the two, with conclusions at one level forming premises at the next. We begin by summarising our general approach, which uses instantiations of an argumentation scheme to provide presumptive justifications for actions, and critical questions to identify arguments which attack these justifications. These arguments and attacks are organised into argumentation frameworks to identify the status of individual arguments. We then discuss the levels of reasoning that occur in this reconstruction and the properties and significance of each of these levels. We illustrate the different levels with short examples and also include a discussion of the role of precedents within these levels of reasoning. (shrink)

Computer science advocates institutional frameworks as an effective tool for modelling policies and reasoning about their interplay. In practice, the rules or policies, of which the institutional framework consists, are often specified using a formal language, which allows for the full verification and validation of the framework (e.g. the consistency of policies) and the interplay between the policies and actors (e.g. violations). However, when modelling large-scale realistic systems, with numerous decision-making entities, scalability and complexity issues arise making it possible (...) only to verify certain portions of the problem without reducing the scale. In the social sciences, agent-based modelling is a popular tool for analysing how entities interact within a system and react to the system properties. Agent-based modelling allows the specification of complex decision-making entities and experimentation with large numbers of different parameter sets for these entities in order to explore their effects on overall system performance. In this paper we describe how to achieve the best of both worlds, namely verification of a formal specification combined with the testing of large-scale systems with numerous different actor configurations. Hence, we offer an approach that allows for reasoning about policies, policy making and their consequences on a more comprehensive level than has been possible to date. We present the institutional agent-based model methodology to combine institutional frameworks with agent-based simulations). We furthermore present J-InstAL, a prototypical implementation of this methodology using the InstAL institutional framework whose specifications can be translated into a computational model under the answer set semantics, and an agent-based simulation based on the jason tool. Using a simplified contract enforcement example, we demonstrate the functionalities of this prototype and show how it can help to assess an appropriate fine level in case of contract violations. (shrink)

Agents act on the basis of their beliefs and these beliefs change as they interact with other agents. In this book the authors propose and explain general logical tools for handling change. These tools include preferential reasoning, theory revision, and reasoning in inheritance systems, and the authors use these tools to examine nonmonotonic logic, deontic logic, counterfactuals, modal logic, intuitionistic logic, and temporal logic. This book will be of benefit to researchers engaged with artificial intelligence, and in particular (...) agents, multiagent systems and nonmonotonic logic. (shrink)

The focus of social simulation on representing the social world calls for an investigation of whether its implementations are inherently value-laden. In this article, I investigate what kind of thing implementation is in social simulation and consider the extent to which it has moral significance. When the purpose of a computational artefact is simulating human institutions, designers with different value judgements may have rational reasons for developing different implementations. I provide three arguments to show that different implementations amount to taking (...) moral stands via the artefact. First, the meaning of a social simulation is not homogeneous among its users, which indicates that simulations have high interpretive malleability. I place malleability as the condition of simulation to be a metaphorical vehicle for representing the social world, allowing for different value judgements about the institutional world that the artefact is expected to simulate. Second, simulating the social world involves distinguishing between malfunction of the artefact and representation gaps, which reflect the role of meaning in simulating the social world and how meaning may or not remain coherent among the models that constitute a single implementation. Third, social simulations are akin to Kroes’ techno-symbolic artefacts, in which the artefact’s effectiveness relative to a purpose hinges not only on the functional effectiveness of the artefact’s structure, but also on the artefact’s meaning. Meaning, not just technical function, makes implementations morally appraisable relative to a purpose. I investigate Schelling’s model of ethnic residential segregation as an example, in which different implementations amount to taking different moral stands via the artefact. (shrink)

Directed reasons are reasons that rely for their normative significance on the authority one individual has with respect to another. Acts such as promising seem to generate such reasons. These reasons seem paradigmatically agent relative: they do not hold for all agents. This paper provides a defense of the claim that theform of agent relativism seemingly required by directed reasons is innocuous, and poses no general problem for a practice dependent account of directed reasons, and, therefore, for consequentialism. (...) While the position I present does not constitute a complete teleological account of value, it points toward a way of integrating directed reasons into a practice-based account of value. The position presented also remains consistent with the so called Compelling Idea that often motivates consequentialism: it is always permissible for an agent to do what will lead to the outcome that is best. (shrink)

In this paper we address the modelling of reasoning processes in natural agents. We focus on a very basic kind of non-monotonic inference for which we identify a simple and plausible underlying process, and we develop a family of logical models that allow to match this process. Partial worlds models, as we call them, are a variant of Kraus, Lehmann and Magidor’s cumulative models. We show that the inference relations they induce form a strict subclass of cumulative relations and (...) tackle the issue of providing sound and complete sets of rules to characterise them. Taking inspiration from the work of Gabbay and Schlechta, we analyse the question in terms of definable sets of partial worlds and conclude that completeness is probably unreachable using a standard propositional language. This brings us to enrich our language with an additional connective, which makes it possible to distinguish between two kinds of disjunction in the partial worlds context. Within this renewed framework, we provide two representation theorems: one for inference relations induced by precisification-free smooth models, and the other for inference relations induced by precisification-free ranked models. Finally we give an aperçu of how partial worlds models lend themselves to the modelling of learning. (shrink)

Several authors have recently begun to apply virtue theory to argumentation. Critics of this programme have suggested that no such theory can avoid committing an ad hominem fallacy. This criticism is shown to trade unsuccessfully on an ambiguity in the definition of ad hominem. The ambiguity is resolved and a virtue-theoretic account of ad hominem reasoning is defended.

Logical pluralism is the view that there is more than one correct logic. A key objection to logical pluralism is that it collapses into monism. The core of the Collapse Objection is that only the pluralist’s strongest logic does any genuine normative work; since a logic must do genuine normative work, this means that the pluralist is really a monist, who is committed to her strongest logic being the one true logic. This paper considers a neglected question in the collapse (...) debate: what is it for a logic to do genuine normative work? As well as having wider upshot for the connection between logic and normativity, grappling with this question provides a new response to the Collapse Objection on behalf of the pluralist. I suggest that we should allow logics to generate pro tanto reasons in a way that bears not just on combinations of attitudes but on how an agent’s attitudes are based on one another. This motivates adopting normative principles that allow the pluralist’s weaker logics to earn their normative keep. Rather than being ad hoc, these principles capture a sense in which good reasoning goes beyond the consistency of an agent’s attitudes. Good reasoning is also concerned with how an agent’s attitudes are based on one another. (shrink)

Agents which perform inferences on the basis of unreliable information need an ability to revise their beliefs if they discover an inconsistency. Such a belief revision algorithm ideally should be rational, should respect any preference ordering over the agent’s beliefs (removing less preferred beliefs where possible) and should be fast. However, while standard approaches to rational belief revision for classical reasoners allow preferences to be taken into account, they typically have quite high complexity. In this paper, we consider belief (...) revision for agents which reason in a simpler logic than full first-order logic, namely rule-based reasoners. We show that it is possible to define a contraction operation for rule-based reasoners, which we call McAllester contraction, which satisfies all the basic Alchourrón, Gärdenfors and Makinson (AGM) postulates for contraction (apart from the recovery postulate) and at the same time can be computed in polynomial time. We prove a representation theorem for McAllester contraction with respect to the basic AGM postulates (minus recovery), and two additional postulates. We then show that our contraction operation removes a set of beliefs which is least preferred, with respect to a natural interpretation of preference. Finally, we show how McAllester contraction can be used to define a revision operation which is also polynomial time, and prove a representation theorem for the revision operation. (shrink)

Practical reasoners are resource-bounded—in particular they require time to derive consequences of their knowledge. Building on the Timed Reasoning Logics (TRL) framework introduced in [1], we show how to represent the time required by an agent to reach a given conclusion. TRL allows us to model the kinds of rule application and conflict resolution strategies commonly found in rule-based agents, and we show how the choice of strategy can influence the information an agent can take into (...) account when making decisions at a particular point in time. We prove general completeness and decidability results for TRL, and analyse the impact of communication in an example system consisting of two agents which use different conflict resolution strategies. (shrink)

Selfish, dishonest or malicious agents may find an interest in manipulating others. While many works deal with designing robust systems or manipulative strategies, few works are interested in defining in a broad sense what is a manipulation and how we can reason with such a notion. In this article, based on a social science literature, we give a general definition of manipulation for multi-agent systems. A manipulation is a deliberate effect of an agent – called manipulator – (...) to instrumentalize another agent – called victim – while making sure to conceal that effect. We present then a logical framework, called KBE, to express and reason about manipulations. Since manipulation relies on deliberate effects, KBE introduces a deliberate BIAT operator which abstracts deliberate consequences of actions. We prove that this logic is sound and complete. Furthermore,we express related notions such as coercion, persuasion, or deception. (shrink)

I propose an account of desire that reconciles two apparently conflicting intuitions about practical agency. I do so by exploring a certain intuitive datum. The intuitive datum is that often when an agent desires P she will seem to immediately and conclusively know that there is a reason to bring P about. Desire-based theories of reasons seem uniquely placed to explain this intuitive datum. On this view, desires are the source of an agent’s practical reasons. A desire (...) for P grounds conclusive knowledge of a reason to bring P about because that desire makes it true that there is a reason to do so. However, this implies that a basic desire for P can never be in error about there being at least some reason to bring P about. We have the conflicting intuition that basic desires sometimes rationally count for nothing. The guise of the good explains this intuition about the fallibility of desires. On this view, a desire for P represents P as good in some respect. Desires and reasons are independent, so a desire might misrepresent one’s reasons. But this independence is usually taken to rule out that desires ever provide conclusive knowledge of reasons. Capturing the intuition about conclusive knowledge rules out capturing the intuition about fallibility, and vice versa. I propose an epistemological disjunctivist version of the guise of the good that reconciles fallibility with the possibility of conclusive knowledge. (shrink)

The agent-relative/agent-neutral distintion is widely and rightly regarded as a philosophically important one. Unfortunately, the distinction is often drawn in different and mutually incompatible ways. The agent-relative/agent-neutral distinction has historically been drawn three main ways: the ‘principle-based distinction’, the ‘reason-statement-based distinction’ and the ‘perspective-based distinction’. Each of these approaches has its own distinctive vices (Sections 1-3). However, a slightly modified version of the historically influential principle-based approach seems to avoid most if not (...) all of these vices (Section 4). The distinction so understood differs from numerous other distinctions with which it might easily be confused (Section 5). Finally, the distinction so drawn is important to normative theorizing for a variety of reasons (Section 6). (shrink)

The logical omniscience problem, whereby standard models of epistemic logic treat an agent as believing all consequences of its beliefs and knowing whatever follows from what else it knows, has received plenty of attention in the literature. But many attempted solutions focus on a fairly narrow specification of the problem: avoiding the closure of belief or knowledge, rather than showing how the proposed logic is of philosophical interest or of use in computer science or artificial intelligence. Sentential epistemic logics, (...) as opposed to traditional possible worlds approaches, do not suffer from the problems of logical omniscience but are often thought to lack interesting epistemic properties. In this paper, I focus on the case of rule-based agents, which play a key role in contemporary AI research but have been neglected in the logical literature. I develop a framework for modelling monotonic, nonmonotonic and introspective rule-based reasoners which have limited cognitive resources and prove that the resulting models have a number of interesting properties. An axiomatization of the resulting logic is given, together with completeness, decidability and complexity results. (shrink)

In this paper, I defend a new theory of normative reasons called reasons as good bases, according to which a normative reason to φ is something that is a good basis for φing. The idea is that the grounds on which we do things—bases—can be better or worse as things of their kind, and a normative reason—a good reason—is something that is just a good instance of such a ground. After introducing RGB, I clarify what it is to be a (...) good basis, and argue that RGB has various attractive features: it has intuitive implications, makes good sense of the weights of reasons, and attractively explains the relationship between normative reasons and motivating reasons. I then briefly defend the view from objections and compare it to rivals. Finally, I sketch two possible implications of RGB: some kind of constitutivism, according to which the norms that govern us are explained by the nature of agency, and second, the claim that agents who do things for reasons generally do them for good reasons. (shrink)

In this paper, we first propose a simple formal language to specify types of agents in terms of necessary conditions for their announcements. Based on this language, types of agents are treated as ‘first-class citizens’ and studied extensively in various dynamic epistemic frameworks which are suitable for reasoning about knowledge and agent types via announcements and questions. To demonstrate our approach, we discuss various versions of Smullyan’s Knights and Knaves puzzles, including the Hardest Logic Puzzle Ever (HLPE) (...) proposed by Boolos (in Harv Rev Philos 6:62–65, 1996). In particular, we formalize HLPE and verify a classic solution to it. Moreover, we propose a spectrum of new puzzles based on HLPE by considering subjective (knowledge-based) agent types and relaxing the implicit epistemic assumptions in the original puzzle. The new puzzles are harder than the previously proposed ones in the literature, in the sense that they require deeper epistemic reasoning. Surprisingly, we also show that a version of HLPE in which the agents do not know the others’ types does not have a solution at all. Our formalism paves the way for studying these new puzzles using automatic model checking techniques. (shrink)

The paper argues that logical reasoning is what constitutes critical thinking because reasoning is normative, and logic provides a norm for reasoning. If a logical way of thinking is simply the same thing as reasoning, then the only limit or constraint of reasoning is the nature of the (logical) “rule” the kind of which is engaged with the practice of reasoning; rather than with either a component of social context or a com- ponent of (...) a purely non-inferential or “immediate” perception of a situation which is called sensitivity toward an object alone. However, such components are built into my analysis of what “reasoning” is. An approach to critical thinking being employed here is “an agent-based approach”. This paper also aims to pave the way for a further discussion on the limit of reasoning in a way that is relevant to the question of how critical thinking or reasoning should be taught in higher education. (shrink)

This book is an analysis of the distinctive form of reasoning, called practical reasoning by Aristotle (as opposed to theoretical reasoning), that serves to guide behaviour.

In this paper, we continued the preparatory works of Jingde Cheng in conjunction with spatio-temporal relevant logics, and proposed several epistemic spatio-temporal relevant logics as basic logics for Mobile Multi-Agent Systems (MMAS). To establish an inference system, important elements are: semantics and syntax appropriate to it include a language, axioms and inference rules. By proving the meta-logical properties such as soundness and consistency, completeness and decidability and etc., we have a method to test the reliability of the systems. Finally, (...) we will have models and algorithms for the application of these logics in the MMAS. (shrink)

There is a surprising disconnect between formal rational choice theory and philosophical work on reasons. The one is silent on the role of reasons in rational choices, the other rarely engages with the formal models of decision problems used by social scientists. To bridge this gap, we propose a new, reason-based theory of rational choice. At its core is an account of preference formation, according to which an agent’s preferences are determined by his or her motivating reasons, together (...) with a ‘weighing relation’ between different combinations of reasons. By explaining how someone’s preferences may vary with changes in his or her motivating reasons, our theory illuminates the relationship between deliberation about reasons and rational choices. Although primarily positive, the theory can also help us think about how those preferences and choices ought to respond to normative reasons. (shrink)

Together we can achieve things that we could never do on our own. In fact, there are sheer endless opportunities for producing morally desirable outcomes together with others. Unsurprisingly, scholars have been finding the idea of collective moral obligations intriguing. Yet, there is little agreement among scholars on the nature of such obligations and on the extent to which their existence might force us to adjust existing theories of moral obligation. What interests me in this paper is the perspective of (...) the moral deliberating agent who faces a collective action problem, i.e. the type of reasoning she employs when deciding how to act. I hope to show that agents have collective obligations precisely when they are required to employ ‘we-reasoning’, a type of reasoning that differs from I-mode, best response reasoning, as I shall explain below. More precisely, two (or more) individual agents have a collective moral obligation to do x if x is an option for action that is only collectively available (more on that later) and each has sufficient reason to rank x highest out of the options available to them. (shrink)

Since e-Commerce has become a discipline, e-Contracts are acknowledged as the tools that will assure the safety and robustness of the transactions. A typical e-Contract is a binding agreement between parties that creates relations and obligations. It consists of clauses that address specific tasks of the overall procedure which can be represented as workflows. Similarly to e-Contracts, Intelligent Agents manage a private policy, a set of rules representing requirements, obligations and restrictions, additionally to personal data that meet their user’s interests. (...) In this context, this study aims at proposing a policy-based e-Contract workflow management methodology that can be used by semantic web agents, since agents benefit from Semantic Web technologies for data and policy exchanges, such as RDF and RuleML that maximize interoperability among parties. Furthermore, this study presents the integration of the above methodology into a multi-agent knowledge-based framework in order to deal with issues related to rules exchange where no common syntax is used, since this framework provides reasoning services that assist agents in interpreting the exchanged policies. Finally, a B2C e-Commerce scenario is presented that demonstrates the added value of the approach. (shrink)

The naturalization of logic aims at a revision of mainstream logic. In this article, I contend it is an urgent task to be completed. This new project will permit a new collaboration between logic and cognitive science. This can be accomplished doing for logic what many decades ago Quine and other philosophers undertook in the case of epistemology. First of all, this article analyzes how the naturalization can be achieved thanks to some insights provided by the recent John Woods’ book (...) Errors of Reasoning: Naturalizing the Logic of Inference; important concepts that regard a naturalized logic are synthetically analyzed: errors, paradigm creep, third-way reasoning, consequence-having and consequence drawing, agent based reasoning. The article also takes advantage of my own studies, which are aimed both at exculpating the negative fallacious character of abduction and at illustrating the EC-model of it, I have recently proposed. Aiming at encouraging the project of naturalization of logic, the article specifically recommends the increase of logical research on abduction, and emphasizes how current philosophical and logical research on human inferences is indebted towards Charles Sanders Peirce, a philosopher whose importance and modernity are too often underestimated. The final part of the article will introduce an analysis of the importance of the so-called optimization of situatedness, a concept that is necessary to understand that maximization of “abducibility”, which characterizes modern science. (shrink)

A love-based reason theory as a new perspective in the debate on practical reasons. Reasons and obligations pervade our lives. The alarm clock gives us a reason to get up in the morning, the expectations of colleagues or clients give us a reason to do our jobs well, the misery in developing countries gives us a reason to donate money, headaches give us a reason to take an aspirin. Looking for unity in variety, philosophers wonder what makes a consideration (...) count as a reason to do something. The nature and source of practical reasons has been debated intensively over the last three decennia in analytic philosophy. This book discusses the three most influential theories in current debates, referred to as the desire-based, the value-based, and the rationality-based theories of practical reasons. The author argues that all three are defective because they overlook the role of what agents care about. (shrink)

First of all I would like to describe inductive and abductive reasoning in the light of the agent–based framework to the aim of clarifying their fallacious character and the role of the so-called ideal systems (logical and computational). Then I will analyze some inductive and abductive types of reasoning that in the perspective of classical and informal logic are defined fallacies. I will describe how in an agent-based reasoning this kind of fallacious (...) class='Hi'>reasoning can in some cases be redefined and considered as a good way of reasoning. Finally, I will illustrate how what I call manipulative abduction can be interpreted as a form of practical reasoning a better understanding of which can furnish a description of human beings as hybrid reasoners in so far they are users of ideal and computational agents. (shrink)

While differing widely in other respects, both neo-Humean and neo-Kantian approaches to normativity embrace an internalist thesis linking reasons for acting to potential motivation. This thesis pushes in different directions depending on the underlying view of the powers of practical reason, but either way it sets the stage for an attack on realist attempts to ground reasons directly in facts about value. How can reasons that are not somehow grounded in motivational features of the agent nonetheless count as reasons (...) for that particular agent, having genuine normative force for her? Won't any realist, externalist view threaten to alienate the individual from the reasons that obtain for her, particularly if she fails (even after rational deliberation) to care about the values that are supposed to ground them? I argue that such objections can successfully be answered, and that externalist views of reasons need not be plagued with normative alienation. Focusing largely on a recent debate between Williams and McDowell over the nature of normative reasons, I show that a value-based externalist theory, when properly conceived, can account for the normative relevance of reasons to the particular agents for whom they obtain. Moreover, Williams's own sophisticated neo-Humeanism turns out to be vulnerable to parallel charges of normative alienation, which it cannot escape without compromising the very psychologistic orientation that has been its chief attraction. Realist externalism about reasons turns out to be a more viable and attractive alternative to both neo-Humeanism and neo-Kantianism than many currently take it to be. (shrink)

In this paper we describe an approach to practical reasoning, reasoning about what it is best for a particular agent to do in a given situation, based on presumptive justifications of action through the instantiation of an argument scheme, which is then subject to examination through a series of critical questions. We identify three particular aspects of practical reasoning which distinguish it from theoretical reasoning. We next provide an argument scheme and an associated set (...) of critical questions which is able to capture these features. In order that both the argument scheme and the critical questions can be given precise interpretations we use the semantic structure of an Action-Based Alternating Transition System as the basis for their definition. We then work through a detailed example to show how this approach to practical reasoning can be applied to a problem solving situation, and briefly describe some other previous applications of the general approach. In a second example we relate our account to the social laws paradigm for co-ordinating multi-agent systems. The contribution of the paper is to provide firm foundations for an approach to practical reasoning based on presumptive argument in terms of a well-known model for representing the effects of actions of a group of agents. (shrink)

This paper proposes an approach to investigate norm-governed learning agents which combines a logic-based formalism with an equation-based counterpart. This dual formalism enables us to describe the reasoning of such agents and their interactions using argumentation, and, at the same time, to capture systemic features using equations. The approach is applied to norm emergence and internalisation in systems of learning agents. The logical formalism is rooted into a probabilistic defeasible logic instantiating Dung’s argumentation framework. Rules of this (...) logic are attached with probabilities to describe the agents’ minds and behaviours as well as uncertain environments. Then, the equation-based model for reinforcement learning, defined over this probability distribution, allows agents to adapt to their environment and self-organise. (shrink)

Under review at Social Epistemology. The normative status of partisan of epistemology has been the subject of much recent philosophical attention. It is often assumed that partisan epistemology is evidence of directionally motivated reasoning in which concerns about group membership override concerns about accuracy. I outline an alternative account which seeks to explain the data assuming people are motivated by accuracy. I argue that this theory offers a superior explanation of partisan epistemology than alternative social-benefits theories of the phenomenon. (...) Since one important benefit of these theories has been taken to be that they’re at a special advantage in accounting for (the patterns of) belief in misinformation, I also argue that this advantage is smaller than it seems. (shrink)

During a dialogue, agents exchange information with each other and need thus to deal with incoming information. For that purpose, they should be able to reason effectively about trustworthiness of information sources. This paper proposes an argument-based system that allows an agent to reason about its own beliefs and information received from other sources. An agent's beliefs are of two kinds: beliefs about the environment and beliefs about trusting sources . Six basic forms of trust are discussed (...) in the paper including the most common one on sincerity. Starting with a base which contains such information, the system builds two types of arguments: arguments in favour of trusting a given source of information and arguments in favour of believing statements which may be received from other agents. We discuss how the different arguments interact and how an agent may decide to trust another source and thus to accept information coming from that source... (shrink)

In A New Form of Agent-Based Virtue Ethics , Daniel Doviak develops a novel agent-based theory of right action that treats the rightness (or deontic status) of an action as a matter of the action’s net intrinsic virtue value (net-IVV)—that is, its balance of virtue over vice. This view is designed to accommodate three basic tenets of commonsense morality: (i) the maxim that “ought” implies “can,” (ii) the idea that a person can do the right thing (...) for the wrong reason, and (iii) the idea that a virtuous person can have “mixed motives.” In this paper, I argue that Doviak’s account makes an important contribution to agent-based virtue ethics, but it needs to be supplemented with a consequentialist account of the efficacy of well-motivated actions—that is, it should be transformed into a mixed (motives-consequences) account, while retaining its net-IVV calculus. This is because I believe that there are right-making properties external to an agent’s psychology which it is important to take into account, especially when an agent’s actions negatively affect other people. To incorporate this intuition, I add to Doviak’s net-IVV calculus a scale for outcomes . The result is a mixed view which accommodates tenets (ii) and (iii) above, but allows for (i) to fail in certain cases. I argue that, rather than being a defect, this allowance is an asset because our intuitions about ought-implies-can break down in cases where an agent is grossly misguided, and our theory should track these intuitions. (shrink)