Overview of fundamental work in deontic logic.

Every adequate semantics for conditionals and deontic ought must offer a solution to the miners paradox about conditional obligations. Kolodny and MacFarlane have recently argued that such a semantics must reject the validity of modus ponens. I demonstrate that rejecting the validity of modus ponens is inessential for an adequate solution to the paradox.

Imperatives occur ubiquitously in natural languages. They produce forces which change the addressee’s cognitive state and regulate her actions accordingly. In real life we often receive conflicting orders, typically, issued by various authorities with different ranks. A new update semantics is proposed in this paper to formalize this idea. The general properties of this semantics, as well as its background ideas are discussed extensively. In addition, we compare our framework with other approaches of deontic logics in the context of normative (...) conflicts. (shrink)

On the face of it, normative conflicts are commonplace. Yet standard deontic logic declares them to be logically impossible. That prompts the question, What are the proper principles of normative reasoning if such conflicts are possible? This paper examines several alternatives that have been proposed for a logic of 'ought' that can accommodate normative conflicts, and finds all of them unsatisfactory as measured against three criteria of adequacy. It then introduces a new logic that does meet all three criteria, and (...) so allows for the possibility of genuine normative conflicts. (shrink)

This paper offers a general model of substantive moral principles as a kind of hedged moral principles that can (but don't have to) tolerate exceptions. I argue that the kind of principles I defend provide an account of what would make an exception to them permissible. I also argue that these principles are nonetheless robustly explanatory with respect to a variety of moral facts; that they make sense of error, uncertainty, and disagreement concerning moral principles and their implications; and that (...) one can grasp these principles without having to grasp any particular list of their permissibly exceptional instances. I conclude by pointing out various advantages that this model of principles has over several of its rivals. The bottom line is that we should find nothing peculiarly odd or problematic about the idea of exception-tolerating and yet robustly explanatory moral principles. (shrink)

According to a popular account, rationality is a kind of coherence of an agent’s mental states and, more specifically, a matter of fulfilling norms of coherence. For example, in order to be rational, an agent is required to intend to do what they judge they ought to and can do. This norm has been called ‘Enkrasia’. Another norm requires that, ceteris paribus, an agent retain their intention over time. This has been called ‘Persistence of Intention’. This paper argues that thus (...) understood norms of rationality may at times conflict. More specifically, Enkrasia and Persistence of Intention may place demands on the agent that are impossible to fulfil. In these cases, the framework of requirements does not provide us with norms that make us rational. A rival account, according to which rationality is a kind of responsiveness to one’s available reasons, can overcome the problem. (shrink)

This is an opinionated guide to the literature on epistemic dilemmas. It discusses seven kinds of situations where epistemic dilemmas appear to arise; dilemmic, dilemmish, and non-dilemmic takes on them; and objections to dilemmic views along with dilemmist’s replies to them.

All of us have personal ideals. We are committed to being good (enough) friends, parents, neighbors, teachers, citizens, human beings, and more. In this paper, I examine the thick and thin aspects of these ideals: (i) their substance (to internalize an ideal is to endorse a particular way of being) and (ii) their accountability to reason (to internalize an ideal is to assume that this is really a good way to be). In considering how these two aspects interact in the (...) ideal of rational agency, I address two philosophical debates that are generally conducted in isolation of each other: (i) debates over the anti-ideal of normative “fetishism” and (ii) debates over whether acting for a reason is acting “under the guise of the good.” In the final two sections of the paper, I further explore the relations among the thick and the thin. I note the role that coherence constraints play in the process whereby our ideals gain determinacy. At the same time, I argue, our ideals constrain the possibility and desirability of coherence. This has implications for a third debate: the debate over the possibility of moral dilemmas. (shrink)

Moral conflicts are the situations which emerge as a response to deal with conflicting obligations or duties. An interesting case arises when an agent thinks that two obligations A and B are equally important, but yet fails to choose one obligation over the other. Despite the fact that the systematic study and the resolution of moral conflicts finds prominence in our linguistic discourse, standard deontic logic when used to represent moral conflicts, implies the impossibility of moral conflicts. This presents a (...) conundrum for appropriate logic to address these moral conflicts. We frequently believe that there is a close connection between tolerating inconsistencies and conflicting moral obligations. In paraconsistent logics, we tolerate inconsistencies by treating them to be both true and false. In this paper, we analyze Graham Priest’s paraconsistent logic LP, and extend our examination to the deontic extension of LP known as DLP. We illustrate our work, with a classic example from the famous Indian epic Mahabharata, where the protagonist Arjuna faces a moral conflict in the battlefield of Kurukshetra. The paper aims to avoid deontic explosion and allows to accommodate Arjuna’s moral conflict in paraconsistent deontic logics. Our analysis is expected to provide novel tools towards the logical representation of moral conflicts and to shed some light on the context-sensitive paraconsistent deontic logic. (shrink)

Could it be true that even though we as a group ought to do something, you as an individual ought not to do your part? And under what conditions, in particular, could this happen? In this article, I discuss how a certain kind of case, introduced by David Copp, illustrates the possibility that you ought not to do your part even when you would be playing a crucial causal role in the group action. This is because you may have special (...) agent-relative reasons against participating that are not shared by the group as a whole. I defend the claim that these are indeed cases in which you ought not to do your part in what the group ought to do. I then argue that we can expect these cases to produce a troubling kind of rational conflict. (shrink)

Reasons-based accounts of our normative conclusions face difficulties in distinguishing between what ought to be done and what is required. This article addresses this problem from a formal perspective. I introduce a rudimentary formalization of a reasons-based account and demonstrate that that the model faces difficulties in accounting for the distinction between oughts and requirements. I briefly critique attempts to distinguish between oughts and requirements by appealing to a difference in strength or weight of reasons. I then present a formalized (...) reasons-based account of permissions, oughts and requirements. The model exploits Joshua Gert (2004; 2007) and Patricia Greenspan’s (2005; 2007; 2010) suggestion that some reasons perform a purely justificatory function. I show that the model preserves the standard entailment relationships between requirements, oughts and permissions. (shrink)

Building on recent formal work by Aleks Knoks, we explore how the idea that certain epistemic norms may be indeterminate could be implemented in a default logic.

This paper shows that our popular account of weakness of will is inconsistent with dilemmas. In dilemmas, agents judge that they ought to do one thing, that they ought to do something else, and that they cannot do both. They must act against either of their two judgments. But such action is commonly understood as weakness of will. An agent is weak-willed in doing something if she judges that she ought to and could do something else instead. Thus, it seems (...) that, in a dilemma, the agent is weak-willed by definition. But this is puzzling: clearly, the two are different phenomena. The puzzle may support scepticism about weakness of will or dilemmas. Here, I argue that the two are consistent on a revised understanding of weakness of will. To do so, I further distinguish the mental states of an agent in a dilemma from those of a weak-willed person. (shrink)

Thinking about misleading higher-order evidence naturally leads to a puzzle about epistemic rationality: If one’s total evidence can be radically misleading regarding itself, then two widely-accepted requirements of rationality come into conflict, suggesting that there are rational dilemmas. This paper focuses on an often misunderstood and underexplored response to this (and similar) puzzles, the so-called conflicting-ideals view. Drawing on work from defeasible logic, I propose understanding this view as a move away from the default metaepistemological position according to which rationality (...) requirements are strict and governed by a strong, but never explicitly stated logic, toward the more unconventional view, according to which requirements are defeasible and governed by a comparatively weak logic. When understood this way, the response is not committed to dilemmas. (shrink)

Sometimes we make mistakes, even when we try to do our best. When those mistakes are about normative matters, such as what is required, this leads to a puzzle. This puzzle arises from the possibility of misleading evidence about what rationality requires. I argue that the best way to solve this puzzle is to distinguish between two kinds of evaluation: requirement and appraisal. The strategy I defend connects three distinct debates in epistemology, ethics, and normativity: the debate over how our (...) theories of epistemic rationality should accommodate misleading evidence, the debate over the relationship between complying with requirements and deserving particular appraisals, and the debate over whether normative ignorance can excuse. Part 1 shows how three apparently plausible claims about epistemic rationality generate a puzzle when agents have misleading evidence about what rationality requires. Part 2 solves this puzzle by distinguishing between evaluations of requirement and appraisal and rejecting the idea that one is required to conform to the Enkratic Principle. I argue instead that complying with the Enkratic Principle provides defeasible evidence that the agent should be positively appraised. One of the consequences of this solution is that false normative beliefs can sometimes excuse agents from negative appraisal they would otherwise deserve for violating requirements. Part 3 defends the view that false normative belief can sometimes excuse against the rival views that false normative belief always excuses, and that false normative belief never excuses. I argue that false normative belief can sometimes excuse violations of requirements, when it is the case that the agent has done what it is reasonable to expect of her. (shrink)

In this paper I focus on a recently discussed phenomenon illustrated by sentences containing predicates of taste: the phenomenon of " perspectival plurality " , whereby sentences containing two or more predicates of taste have readings according to which each predicate pertains to a different perspective. This phenomenon has been shown to be problematic for (at least certain versions of) relativism. My main aim is to further the discussion by showing that the phenomenon extends to other perspectival expressions than predicates (...) of taste and by proposing a general solution to the problem raised by it on behalf of the relativist. The core claim of the solution (" multiple indexing ") is that utterances of sentences containing perspectival expressions should be evaluated with respect to (possibly infinite) sequences of perspective parameters. (shrink)

You shouldn’t have done it. But you did. Against your better judgment you scrolled to the end of an article concerning the state of race relations in America and you are now reading the comments. Amongst the slurs, the get-rich-quick schemes, and the threats of physical violence, there is one comment that catches your eye. Spencer argues that although it might be “unpopular” or “politically incorrect” to say this, the evidence supports believing that the black diner in his section will (...) tip poorly. He insists that the facts don’t lie. The facts aren’t racist. In denying his claim and in believing otherwise, it is you who engages in wishful thinking. It is you who believes against the evidence. You, not Spencer, are epistemically irrational. -/- My dissertation gives an account of the moral-epistemic norms governing belief that will help us answer Spencer and the challenge he poses. We live in a society that has been shaped by racist attitudes and institutions. Given the effects of structural racism, Spencer’s belief could have considerable evidential support. Spencer notes that it might make him unpopular, but he cares about the truth and he is willing to believe the unpopular thing. But, Spencer’s belief seems racist. Spencer asks, however, how could his belief be racist if his beliefs reflect reality and are rationally justified? Moreover, how could he wrong anyone by believing what he epistemically ought to believe given the evidence? In answer, I argue that beliefs can wrong. (shrink)

I defend the view that a reason for someone to do something is just a reason why she ought to do it. This simple view has been thought incompatible with the existence of reasons to do things that we may refrain from doing or even ought not to do. For it is widely assumed that there are reasons why we ought to do something only if we ought to do it. I present several counterexamples to this principle and reject some (...) ways of understanding "ought" so that the principle is compatible with my examples. I conclude with a hypothesis for when and why the principle should be expected to fail. (shrink)

A moral dilemma is a situation where an agent’s obligations conflict. Debate in this area focuses on the question of whether genuine moral dilemmas exist. This question involves considering not only the nature and significance of dilemmas, but also the connections between dilemmas, the logic of obligation and moral emotions.

In this paper I present an argument for the claim that you ought to do something only if you may believe that you ought to do it. More exactly, I defend the following principle about normative reasons: An agent A has decisive reason to φ only if she also has sufficient reason to believe that she has decisive reason to φ. I argue that this principle follows from the plausible assumption that it must be possible for an agent to respond (...) correctly to her reasons. In conclusion, I discuss some implications of this argument (given that some other standard assumptions about reasons hold). One such implication is that we are always in a position to be justified in believing all truths about what we have decisive reason (or ought) to do. (shrink)

One of the popular albeit controversial ideas in the last century of moral philosophy is that what we ought to do is explained by our reasons. And one of the central features of reasons that accounts for their popularity among normative theorists is that they can conflict. But I argue that the fact that reasons conflict actually also poses two closely related problems for this popular idea in moral philosophy. The first problem is a generalization of a problem in deontic (...) logic concerning the existence of conflicting obligations. The second problem arises from a tension between the fact that reasons can conflict and a model of how reasons explain ‘ought’s that has been widely accepted. Having presented each of these problems, I develop a unified solution to them that is informed by results in both ethics and deontic logic. An important implication of this solution is that we must distinguish between derivative and nonderivative reasons and revise our conception how it is that reasons explain ‘ought’s. (shrink)

We present two defeasible logics of norm-propositions (statements about norms) that (i) consistently allow for the possibility of normative gaps and normative conflicts, and (ii) map each premise set to a sufficiently rich consequence set. In order to meet (i), we define the logic LNP, a conflict- and gap-tolerant logic of norm-propositions capable of formalizing both normative conflicts and normative gaps within the object language. Next, we strengthen LNP within the adaptive logic framework for non-monotonic reasoning in order to meet (...) (ii). This results in the adaptive logics LNPr and LNPm, which interpret a given set of premises in such a way that normative conflicts and normative gaps are avoided ‘whenever possible’. LNPr and LNPm are equipped with a preferential semantics and a dynamic proof theory. (shrink)

I address a question in moral metaphysics: How are conflicts between moral obligations possible? I begin by explaining why we cannot give a satisfactory answer to this question simply by positing that such conflicts are conflicts between rules, principles, or reasons. I then develop and defend the “Dispositional Account,” which posits that conflicts between moral obligations are conflicts between the manifestations of obligating dispositions (obligating powers, capacities, etc.), just as conflicts between physical forces are conflicts between the manifestations of (certain) (...) causal dispositions (causal powers, capacities, etc.). This account combines the so-called “moral forces” interpretation of prima facie obligations with a dispositional moral metaphysic according to which the metaphysical grounds of moral obligations are not rules or laws, but rather real, irreducibly dispositional properties (or powers) of moral agents and patients. My principal aims are to offer a theoretically attractive and suitably metaphysical account of conflicts of obligation, and to show that the dispositional moral metaphysic that grounds the Dispositional Account can explain and accommodate plausible normative views that rule- and law-based alternatives cannot, as well as to answer objections that have been pressed against other accounts of moral conflict (especially Ross’s) that appeal to moral dispositions or forces. (shrink)

Conceptual limitations restrict our epistemic options. One cannot believe, disbelieve, or doubt what one cannot grasp. I show how, even granting an epistemic ought-implies-can principle, such restrictions might lead to epistemic dilemmas: situations where each of one’s options violates some epistemic requirement. An alternative reaction would be to take epistemic norms to be sensitive to one’s options in ways that ensure dilemmas never arise. I propose, on behalf of the dilemmist, that we treat puzzlement as a kind of epistemic residue, (...) roughly analogous with guilt, appropriate only when one has violated an epistemic requirement. Sometimes, in bumping up against the limits of one’s concepts, it is appropriate to be puzzled no matter what one believes. Puzzlement can thus play the same role in an epistemic dilemmist’s theory that guilt plays in the theories of many moral dilemmists. (shrink)

This is the book of abstracts of the 19th Brazilian Logic Conferences. The Brazilian Logic Conferences (EBL) is one of the most traditional logic conferences in South America. Organized by the Brazilian Logic Society (SBL), its main goal is to promote the dissemination of research in logic in a broad sense. It has been occurring since 1979, congregating logicians of different fields — mostly philosophy, mathematics and computer science — and with different backgrounds — from undergraduate students to senior researchers. (...) The meeting is an important moment for the Brazilian and South American logical community to join together and discuss recent developments of the field. The areas of logic covered in the conference spread over foundations and philosophy of science, analytic philosophy, philosophy and history of logic, mathematics, computer science, informatics, linguistics and artificial intelligence. Previous editions of the EBL have been a great success, attracting researchers from all over Latin America and elsewhere. -/- The 19th edition of EBL takes place from May 6-10, 2019, in the beautiful city of João Pessoa, at the northeast coast of Brazil. It is conjointly organized by Federal University of Paraíba (UFPB), whose main campus is located in João Pessoa, Federal University of Campina Grande (UFCG), whose main campus is located in the nearby city of Campina Grande (the second-largest city in Paraíba state) and SBL. It is sponsored by UFPB, UFCG, the Brazilian Council for Scientific and Technological Development (CNPq) and the State Ministry of Education, Science and Technology of Paraíba. It takes place at Hotel Luxxor Nord Tambaú, privileged located right in front Tambaú beach, one of João Pessoa’s most famous beaches. (shrink)

I consider a number of reasons one might think we should only accept epistemic dilemmas in our normative epistemology as a last resort and argue that none of them is compelling.

Many theories of rational belief give a special place to logic. They say that an ideally rational agent would never be uncertain about logical facts. In short: they say that ideal rationality requires "logical omniscience." Here I argue against the view that ideal rationality requires logical omniscience on the grounds that the requirement of logical omniscience can come into conflict with the requirement to proportion one’s beliefs to the evidence. I proceed in two steps. First, I rehearse an influential line (...) of argument from the "higher-order evidence" debate, which purports to show that it would be dogmatic, even for a cognitively infallible agent, to refuse to revise her beliefs about logical matters in response to evidence indicating that those beliefs are irrational. Second, I defend this "anti-dogmatism" argument against two responses put forth by Declan Smithies and David Christensen. Against Smithies’ response, I argue that it leads to irrational self-ascriptions of epistemic luck, and that it obscures the distinction between propositional and doxastic justification. Against Christensen’s response, I argue that it clashes with one of two attractive deontic principles, and that it is extensionally inadequate. Taken together, these criticisms will suggest that the connection between logic and rationality cannot be what it is standardly taken to be—ideal rationality does not require logical omniscience. (shrink)

You want to see the concert, but don’t want to take a long drive (even though the concert is far away). Such *strongly conflicting desire ascriptions* are, I show, wrongly predicted incompatible by standard semantics. I then object to possible solutions, and give my own, based on *some-things-considered desire*. Considering the fun of the concert, but ignoring the drive, you want to see the concert; considering the boredom of the drive, but ignoring the concert, you don’t want to take the (...) drive. (shrink)

This paper is about epistemic dilemmas, i.e., cases in which one is doomed to have a doxastic attitude that is rationally impermissible no matter what. My aim is to develop and defend a position according to which there can be genuine rational indeterminacy; that is, it can be indeterminate which principles of rationality one should satisfy and thus indeterminate which doxastic attitudes one is permitted or required to have. I am going to argue that this view can resolve epistemic dilemmas (...) in a systematic way while also enjoying some important advantages over its rivals. (shrink)

John Horty has proposed an approach to reasoning with ought-propositions which stands in contrast to the standard modal approach to deontic logic. Horty’s approach is based on default theories as known from the framework of Default Logic. It is argued that the approach cannot be extended beyond the most simple kinds of default theories and that it fails in particular to account for conditional obligations. The most plausible ways of straightening out the defects of the approach conform to a simple (...) theory of default reasoning in standard deontic language. (shrink)

Moral obligations rest on circumstances. But what are these obligating reasons and in virtue of what are they such reasons? Nomological conceptions define such reasons in terms of moral laws. I argue that one such conception cannot be correct and that others do not support the familiar and plausible view that obligating reasons are pro tanto reasons, either because they entail that this view is false or else because they cannot explain—or even help to explain—how it could be true. I (...) also argue that a particular dispositional conception of obligating reasons does support this view of obligating reasons by enabling an explanation of how it could be true. Moreover, my arguments show that the dispositional moral metaphysic on which this conception is predicated can do something that nomological alternatives cannot: explain why obligating reasons and moral obligations are pro tanto reasons and obligations. (shrink)

In this paper, illocutionary acts of commanding will be differentiated from perlocutionary acts that affect preferences of addressees in a new dynamic logic which combines the preference upgrade introduced in DEUL (dynamic epistemic upgrade logic) by van Benthem and Liu with the deontic update introduced in ECL II (eliminative command logic II) by Yamada. The resulting logic will incorporate J. L. Austin’s distinction between illocutionary acts as acts having mere conventional effects and perlocutionary acts as acts having real effects upon (...) attitudes and actions of agents, and help us understand why saying so can make it so in explicit performative utterances. We will also discuss how acts of commanding give rise to so-called “deontic dilemmas” and how we can accommodate most deontic dilemmas without triggering so-called “deontic explosion”. (shrink)

Moving from simple to increasingly sophisticated candidate cases, I argue against the idea that there can be cases in which, due to no fault of the agent or to any ambiguity regarding how things will go depending on which option is selected, all the options available to an agent are rationally impermissible. Whether there are cases that fit this bill—qualifying as what I will label no-fault-or-ambiguity rational dilemmas—depends on the characteristics of conclusive reasons. My reasoning leads me to the view (...) that a key feature of conclusive reasons is that they capture or ground overall assessments that are relationally significant. I then argue that, while this view does not itself conflict with the most sophisticated candidate cases of purported dilemmas of the relevant sort, following the spirit of the view does lead to a conclusion that blocks counting even these cases as ones in which there is a conclusive reason against every available option. My conclusion is that there is no solid basis for the view that there are cases of no-fault-or-ambiguity rational dilemmas. (shrink)

This article argues that there can be epistemic dilemmas: situations in which one faces conflicting epistemic requirements with the result that whatever one does, one is doomed to do wrong from the epistemic point of view. Accepting this view, I argue, may enable us to solve several epistemological puzzles.

ABSTRACT Recent developments in generating gametes via in vitro gametogenesis (IVG) from induced pluripotent stem cells (iPSCs) and their successful use for reproductive purposes in animals strongly suggest that soon these methods could also be used in human reproduction. At least two questions emerge in this context: (a) if a legislator should permit their use and (b) if ethical claims emerge that support their provision, e.g., by public health care systems. This urges an ethical reflection of the new reproductive options (...) this technique might offer. Since the concept of reproductive freedom is a key aspect for the ethical evaluation of artificial reproductive technologies (ARTs), it is necessary to analyze if the new possibilities emerging from IVG fall within the scope of this concept. The results may constitute a morally relevant difference between different imaginable applications of IVG and potentially justify differences in claims to access this technology. (shrink)

Bernard Williams’ critique of the morality system, as illustrated in his reading of Aeschylus’ Agamemnon, is intended to show both that real moral conflicts can arise, and that a moral obligation is merely one reason among others and can be defeated by the thick concepts of a shared ethical life. In response, I want to advance two lines of argument. First, when Williams argues that a moral obligation can be the locus of moral conflict, a further step is required to (...) explain why one should feel regret for not acting on a defeated reason. Second, Williams presupposes that, when a conflict is resolved, the conclusive reason will be a thick ethical concept, but there is no compelling justification for that assumption. (shrink)

What I refer to here as the dilemma of authority arises when one ought to defer to authority; one ought to act as the more weighty reason demands; one can do either; one cannot do both. For those who reject the possibility of legitimate authority, the dilemma does not arise. Among those who accept legitimate authority, some, including Joseph Raz, presume the conflict can be resolved without remainder. In this paper, I argue that, in a moral conflict of this kind, (...) when one of the reasons for action is defeated but not cancelled, it is rational to feel regret for failing to do what one ought to do. (shrink)

Abstract:One view of practical reasoning is that it involves the weighing of reasons. It is not clear, however, how the weights of reasons combine, especially given the logical and substantive relations among different reasons. Nor is it clear how the weighing of reasons relates to decision theoretic maximization of expected value. This paper constructs a formal model of reasons and their weight in order to shed light on these issues. The model informs philosophical debates about reasons, such as the question (...) of whether reasons or values are more fundamental and the opposing doctrines of atomism and holism about reasons. (shrink)

We present the inconsistency-adaptive deontic logic DP r , a nonmonotonic logic for dealing with conflicts between normative statements. On the one hand, this logic does not lead to explosion in view of normative conflicts such as O A ∧ O ∼A, O A ∧ P ∼A or even O A ∧ ∼O A. On the other hand, DP r still verifies all intuitively reliable inferences valid in Standard Deontic Logic (SDL). DP r interprets a given premise set ‘as normally (...) as possible’ with respect to SDL. Whereas some SDL-rules are verified unconditionally by DP r , others are verified conditionally. The latter are applicable unless they rely on formulas that turn out to behave inconsistently in view of the premises. This dynamic process is mirrored by the proof theory of DP r. (shrink)

When a conflict of duties arises, a resolution is often sought by use of an ordering of priority or importance. This paper examines how such a conflict resolution works, compares mechanisms that have been proposed in the literature, and gives preference to one developed by Brewka and Nebel. I distinguish between two cases – that some conflicts may remain unresolved, and that a priority ordering can be determined that resolves all – and provide semantics and axiomatic systems for accordingly defined (...) dyadic deontic operators. (shrink)