This paper contains a survey of the main definitions and results obtained to date related to Temporal Equilibrium Logic, a nonmonotonic hybrid approach that combines Equilibrium Logic (the best-known logical characterisation for the stable models semantics of logic programs) with Linear-Time Temporal Logic.

In this paper, we study the introduction of modal past temporal operators in Temporal Equilibrium Logic, an hybrid formalism that mixes linear-time modalities and logic programs interpreted under stable models and their characterisation in terms of Equilibrium Logic. We show that Kamp’s translation can also be used to translate the new extension of TEL with past operators into Quantified Equilibrium Logic. Additionally, we provide a method for removing past operators that consists in replacing (...) past-time subformulas by fresh auxiliary atoms, obtaining an equivalent formula, modulo the original alphabet. (shrink)

1. Reasoning about action and change, or more generally reasoning about dynamic systems, is not only central to knowledge representation and reasoning but at the heart of computer science (Fisher e...

Among the areas of knowledge that the method of reflective equilibrium (RE) has been applied to is that of logical validity. According to RE in logic, we come to be justified in believing a (deductive) logical theory in virtue of establishing some state of equilibrium between our initial judgements over the validity of specific (natural language) arguments and the logical principles which constitute our logical theory. Unfortunately, however, while relatively popular, RE with regards to logical theorizing is (...) underspecified. In particular, it’s unclear what constitute: (1) the relevant logical “data”, (2) logical theories, so that they can be suitably tested, and (3) the mechanisms under which such theories are tested. Considering the various options for how to interpret the position, we argue that in order to be workable the advocate of RE about logic must embrace what we call an _operationalised_, _wide_ and _communal_ version of RE with a _rich_ understanding of logical theories. Fortunately for the advocate of RE, there is an available account of logic’s epistemology which possesses just these properties, _logical predictivism_. However, equally unfortunately, logical predictivism commits the advocate of RE to certain further claims that they have historically been weary of holding. Consequently, it is unclear whether RE about logic itself is a viable proposal, or rather a similar but distinct epistemology of logic. (shrink)

This book offers a comprehensive account of logic that addresses fundamental issues concerning the nature and foundations of the discipline. The authors claim that these foundations can not only be established without the need for strong metaphysical assumptions, but also without hypostasizing logical forms as specific entities. They present a systematic argument that the primary subject matter of logic is our linguistic interaction rather than our private reasoning and it is thus misleading to see logic as revealing (...) "the laws of thought". In this sense, fundamental logical laws are implicit to our "language games" and are thus more similar to social norms than to the laws of nature. Peregrin and Svoboda also show that logical theories, despite the fact that they rely on rules implicit to our actual linguistic practice, firm up these rules and make them explicit. By carefully scrutinizing the project of logical analysis, the authors demonstrate that logical rules can be best seen as products of the so called reflective equilibrium. They suggest that we can profit from viewing languages as "inferential landscapes" and logicians as "geographers" who map them and try to pave safe routes through them. This book is an essential resource for scholars and researchers engaged with the foundations of logical theories and the philosophy of language. (shrink)

I distinguish two ways of developing anti-exceptionalist approaches to logical revision. The first emphasizes comparing the theoretical virtuousness of developed bodies of logical theories, such as classical and intuitionistic logic. I'll call this whole theory comparison. The second attempts local repairs to problematic bits of our logical theories, such as dropping excluded middle to deal with intuitions about vagueness. I'll call this the piecemeal approach. I then briefly discuss a problem I've developed elsewhere for comparisons of logical theories. Essentially, (...) the problem is that a pair of logics may each evaluate the alternative as superior to themselves, resulting in oscillation between logical options. The piecemeal approach offers a way out of this problem andthereby might seem a preferable to whole theory comparisons. I go on to show that reflective equilibrium, the best known piecemeal method, has deep problems of its own when applied to logic. (shrink)

Though, at first sight, logical formalization of natural language sentences and arguments might look like an unproblematic enterprise, the criteria of its success are far from clear and, surprisingly, there have only been a few attempts at making them explicit. This paper provides a picture of the enterprise of logical formalization that does not conceive of it as a kind of translation from one language (a natural one) into another language (a logical one), but rather as a construction of a (...) 'map' of (a piece of) the 'inferential landscape' of the natural language. The criteria that appear to govern the enterprise are labeled as those of reliability, ambitiousness, transparency and parsimony. These criteria, it is argued, do not provide for an excavation of a ready-made logical structure, but rather help us achieve a "reflective equilibrium" between the normative authority of logic and the answerability of logic to a natural language. (shrink)

Two challenges to the method of reflective equilibrium have been developed in a dispute between Michael D. Resnik and Stewart Shapiro: because the method itself involves logical notions, it can neither be specified in a logic-neutral way nor can it allow logical pluralism. To analyse and answer these claims, an explicit distinction is introduced between judgements held prior to the process of mutual adjustments and judgements in agreement with the systematic principles, which result from the process. It is (...) then argued that from the presystematic perspective, the method of reflective equilibrium permits developing and justifying rival logics, and hence it allows reasonable disagreement about logics; but such pluralism is no longer available from the perspective of fully developed logical systems. (shrink)

We introduce a deductive system Bal which models the logic of balance of opposing forces or of balance between conflicting evidence or influences. ‘‘Truth values’’ are interpreted as deviations from a state of equilibrium, so in this sense, the theorems of Bal are to be interpreted as balanced statements, for which reason there is only one distinguished truth value, namely the one that represents equilibrium. The main results are that the system Bal is algebraizable in the sense (...) of [5] and its equivalent algebraic semantics BAL is definitionally equivalent to the variety of abelian lattice ordered groups, that is, the categories of the algebras in BAL and of ℓ–groups are isomorphic (see [10], Ch.4, 4). We also prove the deduction theorem for Bal and we study different kinds of semantic consequence associated to Bal. Finally, we prove the co-NP-completeness of the tautology problem of Bal. (shrink)

Resenha do livro Reflective Equilibrium and the Principles of Logical Analysis de Jaroslav Peregrin e Vladimir Svoboda publicado em 2017.

Reflective equilibrium and the principles of logical analysis: Understanding the laws of logic. By Peregrin Jaroslav, Svoboda Vladimír.

As Helen Longino's overview of Hypatia's engagement with feminist epistemology suggests, the last twenty-five years’ contributions to this field reveal a strong focus on the topic of knowledge. In her short outline, Longino questions this narrow focus on knowledge in epistemological inquiry. The main purpose of this article is to provide a framework for systematically taking up the questions raised by Longino, one that prevents us from running the risk of becoming unreflectively involved in sexist, racist, or otherwise problematic inquiry. (...) I argue that a specific form of the method of Reflective Equilibrium, as it is widely discussed in moral epistemology, logic, and theories of rationality, enables us to cope with the problems of traditional epistemology, which feminist theorizers such as Sally Haslanger have pointed to. With the account of Reflective Equilibrium I am offering—drawing in many respects on the model provided by Catherine Z. Elgin—we have an ameliorative method that allows us to rethink epistemological values, goals, and standards in a systematic way, and that largely avoids implicit and explicit biases in epistemology. (shrink)

This paper studies an economy whose agents perceive their consumption possibilities subjectively, and whose preferences are defined on what they subjectively experience, rather than on those alternatives that are objectively present. The model of agents' perceptions is based on intuitionistic logic. Roughly, this means that agents reason constructively: a solution to a problem exists only if there is a construction by which the problem can be solved. The theorems that can be proved determine how an agent perceives a set (...) of alternatives. A dual model relates perceived alternatives to a shared language, which the agents use in trading. So perceptions relate objective alternatives to an agent's subjective view of them, and reporting dually relates an agent's subjective world to a shared language. It turns out that an appropriately modified notion of competitive equilibrium always exists. However, in contrast with standard results in economic theory, competitive equilibrium need not be efficient. (shrink)

Reflective equilibrium, as a methodology for the "formation of logics," fails on the *fringe*, where intricate details can make or break a logical theory. On the fringe, the process of theorification cannot be methodologically governed by anything like reflective equilibrium. When logical theorising gets tricky, there is nothing on the pre-theoretical side on which our theoretical claims can reflect of---at least not in any meaningful way. Indeed, the fringe is exclusively the domain of theoretical negotiations and the methodological (...) power of reflective equilibrium is merely nominal. (shrink)

There are two general classes of social conventions: conventions of coordination, and conventions of partial conflict. In coordination problems, the interests of the agents coincide, while in partial conflict problems, some agents stand to gain only if other agents unilaterally make certain sacrifices. Lewis' (1969) pathbreaking analysis of convention in terms of game theory focuses on coordination problems, and cannot accommodate partial conflict problems. In this paper, I propose a new game-theoretic definition of convention which generalizes previous game-theoretic definitions (Lewis (...) 1969, Vanderschraaf 1995), and which can be used to characterize norms of justice in partial conflict situations. I argue that the key structural property necessary for a social arrangement to be a convention is that it be conditionally self-enforcing, in the sense that: (i) each agent has a decisive reason to follow her end of the arrangement given that she expects all to do likewise, (ii) given a different set of expectations, some agents would have had a decisive reason to deviate, and (iii) these facts are common knowledge. This leads to a definition of convention as a strict correlated equilibrium (Aumann 1974) together with appropriate common knowledge conditions. Examples are given in which it is shown how this more general account of convention can be used to analyze norms of justice as well as coordination problems. It is only a general sense of common interest; which sense all the members of the society express to one another, and which induces them to regulate their conduct by certain rules. I observe, that it will be for my interest to leave another in the possession of his goods, provided he will act in the same manner with regard to me. He is sensible of a like interest in the regulation of his conduct. When this common sense of interest is mutually express'd, and is known to both, it produces a suitable resolution and behavior. And this may properly be call'd a convention or agreement betwixt us,.. (shrink)

In this paper, we introduce a new approach to independent quantifiers, as originally introduced in Informational independence as a semantic phenomenon by Hintikka and Sandu [9] under the header of independence-friendly languages. Unlike other approaches, which rely heavily on compositional methods, we shall analyze independent quantifiers via equilibriums in strategic games. In this approach, coined equilibrium semantics, the value of an IF sentence on a particular structure is determined by the expected utility of the existential player in any of (...) the game’s equilibriums. This approach was suggested in Henkin quantifiers and complete problems by Blass and Gurevich [2] but has not been taken up before. We prove that each rational number can be realized by an IF sentence. We also give a lower and upper bound on the expressive power of IF logic under equilibrium semantics. (shrink)

In political philosophy, reflective equilibrium is a standard method used to systematically reconcile intuitive judgments with theoretical principles. In this paper, we propose that survey experiments and a model selection method—i.e., the Akaike Information Criterion (AIC)-based model selection method—can be viewed together as a methodological means of satisfying the epistemic desiderata implicit in reflective equilibrium. To show this, we conduct a survey experiment on two theories of distributive justice, prioritarianism and sufficientarianism. Our experimental test case and AIC-based model (...) selection method demonstrate that the refined sufficientarian principle, a widely accepted principle of distributive justice, is no more plausible than the prioritarian principle. This tells us that some changes of certain intuitions revolving around sufficientarianism should be examined (separately) based on the findings of the survey experiment and AIC model selection. This shows the potential of our approach—both practically and methodologically—as a novel way of applying reflective equilibrium in political philosophy. (shrink)

Although democratic innovations are spread all over the world, there is little research on the institutional outcomes of implementing such innovations in governmental organisations. To remedy this, it is important to focus on cases where DIs have been implemented and formally connected to the policymaking process over a longer period. Reykjavik provides such a case. Drawing on observations and interviews with key stakeholders over a period of three years, this study analyses how the institutional logic of DIs influenced the (...) local government in Reykjavik. The study presents two conclusions: First, it is clear that one equilibrium has not been replaced by another. Second, there is no peaceful co-existence between the two, but instead the outcome is an organisation in ‘a state of flux’. There are several factors contributing to this outcome, but three stand out: a populist power-shift, dissatisfaction with theworking of the implemented DIs and deliberative ambiguity. In the final part of the article, the institutional outcome is discussed in relation to overall consequences for the political system. (shrink)

This paper aims to flesh out the celebrated notion of reflective equilibrium within a probabilistic framework for epistemic rationality. On the account developed here, an agent's attitudes are in reflective equilibrium when there is a certain sort of harmony between the agent's credences, on the one hand, and what the agent accepts, on the other hand. Somewhat more precisely, reflective equilibrium is taken to consist in the agent accepting, or being prepared to accept, all and only claims (...) that follow from a maximally comprehensive theory that is more probable than any other such theory. Drawing on previous work, the paper shows that when an agent is in reflective equilibrium in this sense, the set of claims they accept or are prepared to accept is bound to be logically consistent and closed under logical implication. The paper also argues that this account can explain various features of philosophical argumentation in which the notion of reflective equilibrium features centrally, such as the emphasis on evaluating philosophical theories holistically rather than in a piecemeal fashion. (shrink)

Our scientific theories, like our cognitive structures in general, consist of propositions linked by evidential, explanatory, probabilistic, and logical connections. Those theoretical webs ‘impinge on the world at their edges,’ subject to a continuing barrage of incoming evidence. Our credences in the various elements of those structures change in response to that continuing barrage of evidence, as do the perceived connections between them. Here we model scientific theories as Bayesian nets, with credences at nodes and conditional links between them modelled (...) as conditional probabilities. We update those networks, in terms of both credences at nodes and conditional probabilities at links, through a temporal barrage of random incoming evidence. Robust patterns of punctuated equilibrium, suggestive of ‘normal science’ alternating with ‘paradigm shifts,’ emerge prominently in that change dynamics. The suggestion is that at least some of the phenomena at the core of the Kuhnian tradition are predictable in the typical dynamics of scientific theory change captured as Bayesian nets under even a random evidence barrage. (shrink)

The paper focuses on conceptual images of the market built on the core idea of equilibrium. It argues that logical difficulties and dead ends were encountered in building equilibrium models of the market. A heavy toll was paid in loss of realism, failure to understand history, and ineptitude in addressing relevant problems. Equilibrium economics is marked by the exclusion of a wide range of economic phenomena, with a codified lack of attention to change, transition and learning. The (...) loss of relevance involved was a consequence of the primitive idea of conceiving of the market within the semantic field of equilibrium. The most evident failure of the equilibrium imagery was in understanding economic development as a process of social and structural change in history. The paper argues that is time to free economic theory from the obsessive centrality of the equilibrium idea. Attention should shift to the market economy as a complex network of rules, organizations and institutions, which make viable economic change. This approach invites scholars in economics to a fruitful dialogue with other fields of knowledge, to understand both crises and successes in processes of economic change.L’article traite des images conceptuelles du marché construites à partir de l’idée d’équilibre. Il est suggéré que la construction des modèles d’équilibre du marché a souffert de difficultés logiques et a aboutit à des impasses. Il en a résulté une perte de réalisme, et une incapacité à comprendre l’histoire et à aborder les questions pertinentes. L’économie de l’équilibre est caractérisée par l’exclusion d’un grand nombre de phénomènes économiques mais aussi par un manque d’attention au changement, à la transition, et à l’apprentissage. Le manque de pertinence qui en découle est le résultat de l’idée primitive de concevoir le marché dans le champ sémantique de l’équilibre. L’échec le plus évident de l’image d’équilibre réside dans la compréhension du développement économique comme un processus du changement social et structurel au cours de l’histoire. L’article suggère qu’il est temps de libérer la théorie économique de cette idée obsessionnelle d’équilibre. Il faut plutôt concevoir le marché comme un réseau complexe de règles, d’organisations et d’institutions qui rendent le changement économique viable. Cette approche invite l’économie à un dialogue fructueux avec les autres domaines de la connaissance pour comprendre à la fois les crises et les réussites des processus de changement économique. (shrink)

For some time now, the study of cognitive development has been far and away the most active discipline within developmental psychology. Although there would be much disagreement as to the exact proportion of papers published in develop mental journals that could be considered cognitive, 50% seems like a conservative estimate. Hence, a series of scholarly books devoted to work in cognitive devel opment is especially appropriate at this time. The Springer Series in Cognitive Development contains two basic types of books, (...) namely, edited collections of original chapters by several authors, and original volumes written by one author or a small group of authors. The flagship for the Springer Series is a serial publication of the "advances" type, carrying the subtitle Progress in Cognitive Development Research. Each volume in the Progress sequence is strongly thematic, in that it is limited to some well-defined domain of cognitive developmental research (e.g., logical and mathematical development, development of learning). All Progress volumes will be edited collections. Editors of such collections, upon consultation with the Series Editor, may elect to have their books published either as contributions to the Progress sequence or as separate volumes. All books written by one author or a small group of authors are being published as separate volumes within the series. (shrink)

The purpose of this paper is to make progress on the theoretical discussions about marketing systems in relation to the construction of the concept of equilibrium. An argumentative basis was developed in relation to the service-dominant logic, as well as propositions based on the theory of stakeholders, on distributive justice and on the discussion of externalities to consider the product as an agent of the marketing system. In addition, a product typology that sees life as a material basis (...) for delivering a performance developed, arguing that systems based on this kind of materiality require a different moral consideration. (shrink)

There has been a recent surge of interest among economists in developing models of doxastic states that can account for some aspects of human cognitive limitations that are ignored by standard formal models, such as awareness. Epistemologists purport to have a principled reason for ignoring the question of awareness: under the equilibrium conception of doxastic states they favour, a doxastic state comprises the doxastic commitments an agent would recognise were he fully aware, so the question of awareness plays no (...) role. The objective of this paper is to scrutinize this argument. A thesis underlying the argument, which we call the independence of doxastic commitments with respect to awareness, is identified, and examples are given where it appears to be violated. By considering these examples, one can get an idea of the price of accepting this thesis. On the one hand, one can escape the conclusion that the thesis is violated, but only at the expense of another principle espoused by all major formal models of belief, which we call constant doxastic rest; and abandoning this principle necessitates extensive revision of current models of belief. On the other hand, there are epistemologically valid reasons for thinking that the thesis fails to hold in the examples, which have to be rebutted if the thesis, and the equilibrium justification for ignoring the issue of awareness, are to be retained. (shrink)

About a century ago, Ernst Mach argued that Archimedes’s deduction of the principle of the lever is invalid, since its premises contain the conclusion to be demonstrated. Subsequently, many scholars defended Archimedes, mostly on historical grounds, by raising objections to Mach’s reconstruction of Archimedes’s deduction. In the debate, the Italian philosopher and historian of science Giovanni Vailati stood out. Vailati responded to Mach with an analysis of Archimedes’s deduction which was later quoted and praised by Mach himself. In this paper, (...) my objective is to show that the debate can be further advanced, as Mach indicated, by reframing it in terms of the empirical vs. the logical dimensions of mechanics. In this way, I will suggest, the debate about Archimedes’s deduction can be resolved in Mach’s favour.Keywords: Equilibrium; Experience; Thought experiment; Archimedes; Ernst Mach; Giovanni Vailati. (shrink)

This volume recreates the received notion of reflective equilibrium. It reconfigures reflective equilibrium as both a cognitive ideal and a method for approximating this ideal. The ideal of reflective equilibrium is restructured using the concept of discursive strata, which are formed by sentences and differentiated by function. Sentences that perform the same kind of linguistic function constitute a stratum. The book shows how moral discourse can be analyzed into phenomenal, instrumental, and teleological strata, and the ideal of (...) reflective equilibrium reworked in these terms. In addition, the work strengthens the method of reflective equilibrium by harnessing the resources of decision theory and inductive logic. It launches a comparative version of decision theory and employs this framework as a guide to moral theory choice. It also recruits quantitative inductive logic to inform a standard of inductive cogency. When used in tandem with comparative decision theory, this standard can aid in the effort to turn the undesirable condition of reflective disequilibrium into reflective equilibrium. (shrink)

I propose that a logical formalization of a natural language text may be regarded as adequate if the following three groups of beliefs can be integrated into a wide reflective equilibrium: our initial, spontaneous beliefs about the structure and logical quality of the text; our beliefs about its structure and logical quality as reflected in the proposed formalization, and our background beliefs about the original text’s author, his thought and other contextually relevant factors. Unlike a good part of the (...) literature, I stress the indispensable role of initial beliefs in achieving such a wide reflective equilibrium. In the final sections I show that my approach does not succumb to undue subjectivism or the mere perpetuation of prejudice. The examples I use to illustrate my claims are chiefly taken from Anselm’s Proslogion 2–3 and the various attempts to formalize these texts. (shrink)

Traditional logical reconstruction of arguments aims at assessing the validity of ordinary language arguments. It involves several tasks: extracting argumentations from texts, breaking up complex argumentations into individual arguments, framing arguments in standard form, as well as formalizing arguments and showing their validity with the help of a logical formalism. These tasks are guided by a multitude of partly antagonistic goals, they interact in various feedback loops, and they are intertwined with the development of theories of valid inference and adequate (...) formalization. This paper explores how the method of reflective equilibrium can be used for modelling the complexity of such reconstructions and for justifying the various steps involved. The proposed approach is illustrated and tested in a detailed reconstruction of the beginning of Anselm’s De casu diaboli. (shrink)

The basic idea of logical expressivism in the Brandomian tradition is that logic makes inferential relations explicit and thereby accessible to critical discussion. But expressivists have not given a convincing explanation of what the point of logical theories is. Peregrin provides a starting point by observing a distinction between making explicit and explication in Carnap’s sense of replacing something unclear and vague by something clear and exact. Whereas logical locutions make inferential relations explicit within a language, logical theories use (...) formal languages to explicate inferential roles and meanings of ordinary-language expressions. But Peregrin also holds that the whole point of logical theories is to provide perspicuous models of inferential structures in ordinary language practice. This turns explication into a mere continuation of making explicit by other means, and it leads to a one-sided conception of logic which has no room for evaluating inferential practice in light of logical theories. As a more convincing alternative, I suggest that expressivists rely on the method of reflective equilibrium. This approach is closely related to Carnapian explication, but it has the potential of correcting informal inferential practice without dubious ambitions to replace ordinary languages by logical formalisms. (shrink)

How does Bayesian reasoning support participation in a game's Nash equilibrium? This paper provides an answer.

The special composition question, which asks under which conditions objects compose a further object, establishes a central debate in modern metaphysics. Recent successes of inductive metaphysics, which studies the implications of the natural sciences for metaphysical problems, suggest that insights into the SCQ can be gained by investigating the physics of composite systems. In this work, I show that the minus first law of thermodynamics, which is concerned with the approach to equilibrium, leads to a new approach to the (...) SCQ, the thermodynamic composition principle : Multiple systems in thermal contact compose a single system. This principle, which is justified based on a systematic classification of possible mereological models for thermodynamic systems, might form the basis of an inductive argument for universalism. A formal analysis of the TCP is provided on the basis of mereotopology, which is a combination of mereology and topology. Here, “thermal contact” can be analyzed using the mereotopological predicate “self-connectedness”. Self-connectedness has to be defined in terms of mereological sums to ensure that scattered objects cannot be self-connected. (shrink)

1. A. Heyting (1930) introduced an intermediate logic whose semantics is based on a pair of states (‘here’ and ‘there’). This logic was axiomatized by Hosoi (1966), using the sequence of intermedia...

Rawls’ notion of reflective equilibrium has a hybrid character. It is embedded in the pragmatist tradition, but also includes various Kantian and other non-pragmatist elements. I argue that we should discard all non-pragmatist elements and develop reflective equilibrium in a consistently pragmatist manner. I argue that this pragmatist approach is the best way to defend reflective equilibrium against various criticisms, partly by embracing the critiques as advantages. I begin with discussing how each of the three versions of (...) reflective equilibrium in Rawls’ work combines pragmatist and non-pragmatist elements. For Rawls, the primary purpose of reflective equilibrium is epistemic: namely, to construct moral theories or judgments. In a pragmatist approach, there are three connected purposes for moral inquiry: right action, reliable understanding and self-improvement. Depending on the specific context of a reflective equilibrium process, these general purposes can give rise to a variety of specific purposes. In the next sections, I develop a pragmatist approach to reflective equilibrium and discuss the implications of this approach for core elements of reflective equilibrium. These elements are: the initial convictions, facts, personal commitments and comprehensive views of life, coherence and additional methods for critical scrutiny. (shrink)

I propose that logic may be seen as a science of patterns—however, not in the sense in which mathematics is a science of patterns, but rather in the sense in which physics is. The proposal is that logic identifies, explores, and fixes the inferential patterns which de facto govern our argumentative practices. It can be seen, I argue, as picking up the patterns and working from them toward the state of reflective equilibrium, where the laws it aims (...) at are explicitly articulated. Due to the normativity of logic, this process is not quite the same as that in which a natural science works its way from data to its laws; however, there is no reason why it should be seen as proceeding via a mysterious "a priori analysis.” Instead, it should proceed in the intersubjective space in which the sciences are practiced. (shrink)

It is undeniable that people have beliefs about what actions are morally right. These beliefs play an important role in guiding moral action. Is it possible however to justify beliefs about what actions are morally right? How can beliefs of this sort be justified? Sinnott-Armstrong has advanced an epistemic regress argument against the justification of moral beliefs with the consequence that moral beliefs cannot be justified. This essay addresses the issue of the justification of moral beliefs to answer the question (...) about how moral beliefs can be justified in response to Sinnott-Armstrong’s epistemic regress argument. It argues for the plausibility of Rawls’ reflective equilibrium as an adequate method of justification of moral beliefs. Three problems arise in the attempt to show that reflective equilibrium can adequately respond to Sinnott-Armstrong’s regress argument. These are vicious circularity, arbitrariness and epistemic moral disagreement. It is shown in this essay that these problems can be satisfactorily dealt with. (shrink)

I take 'informal logic' to be the (descriptive and normative) study of 'real arguments'-arguments which are or have been used with the aim of convincing others of a point of view. I argue that the informal logic tradition thus conceived (i) lends strong support to something like Quine's view that our beliefs really support one another like the filaments in a spider's web--and thus that the traditional view that implication is an asymmetric relation is false; (ii) suggests that (...) the classic division of arguments into deductive and inductive has distorted our thinking about the evaluation of real arguments; and (iii) implies that naturalised epistemology is on the right track. (shrink)

We develop a multi-agent deontic action logic to study the logical behaviour of two types of deontic conditionals: (1) conditional obligations, having the form "If group H were to perform action aH, then, in group F's interest, group G ought to perform action aG" and (2) conditional permissions, having the form "If group H were to perform action aH, then, in group F's interest, group G may perform action aG". First, we define a formal language for multi-agent deontic action (...) logic and a class of consequentialist models to interpret the formulas of the language. Second, we define a transformation that converts any strategic game into a consequentialist model. Third, we show that an outcome a* is a Nash equilibrium of a strategic game if and only if a conjunction of certain conditional permissions is true in the consequentialist model that results from the transformation of that strategic game. (shrink)