Centered around the analysis of the prescriptive portion of the Vedas, the Sanskrit philosophical school of Mīmāṃsā provides a treasure trove of normative investigations. We focus on the leading Mīmāṃsā authors Prabhākara, Kumārila and Maṇḍana, and discuss three modal logics that formalize their deontic theories. In the first part of this paper, we use logic to analyze, compare and clarify the various solutions to the _śyena_ controversy, a two-thousand-year-old problem arising from seemingly conflicting commands in the Vedas. In the second (...) part, the formalized Mīmāṃsā theories are analyzed and employed to provide alternative perspectives on well-known paradoxes from the contemporary field of deontic logic. Thus, we go from logic to Mīmāṃsā and back again. (shrink)

Moral obligation and permissibility are usually thought to be interdefinable. Following the pattern of the duality definitions of necessity and possibility, we have that something’s being permissible could be defined as its not being obligatory to not do it. And that something’s being obligatory could be defined as its not being permissible to not do it. In this paper, I argue that neither direction of this alleged interdefinability works. Roughly, the problem is that a claim that some act is obligatory (...) or permissible entails that there is a moral law, whereas a negative claim that some act is not obligatory or not permissible does not. Nevertheless, one direction of the interdefinability can potentially be salvaged. I argue that, if we do not require the conceptual possibility of moral dilemmas, then there is a way to plausibly define obligation in terms of permissibility. I conclude that permissibility is the only feasible deontic primitive. (shrink)

A fitting-attitude analysis which understands value in terms of reasons and pro- and con-attitudes allows limited wriggle room if it is to respect a radical division between good and good-for. Essentially, its proponents can either introduce two different normative notions, one relating to good and the other to good-for, or distinguish two kinds of attitude, one corresponding to the analysis of good and the other to good-for. It is argued that whereas the first option faces a counterintuitive scope issue, an (...) attitudinal approach couched in terms of ‘for someone's sake’ attitudes has the unwelcome consequence that whatever is good for someone is also necessarily good. It is argued that this consequence can be avoided if we modify the standard way of formulating the fitting-attitude analysis of final impersonal value. (shrink)

This chapter provides a selective survey of prominent theories of the semantics of deontic modals in logic and natural language. We focus on Kratzer’s (1977; 1981; 1991) semantics and extensions to this analysis. Kratzer’s semantics has been far and away the most influential theory of deontic modals, which provide a base case for the interpretation of normative language in general. Understanding the logic and truth-conditions of normative language is one of the core areas of metaethics. It informs our understanding of (...) normative arguments and normative reasoning. As this chapter will emphasize, some forms of normative language don’t allow for the inferences that classical logic trains philosophers to expect. Understanding what inferences are valid for normative language should impact our under-standing of how we reason, and should reason, about the normative. We will first look at how deontic modals are understood in the context of modal logic and natural language. Then we’ll survey some recent debates and discoveries in the literature on deontic modals in natural language. We close with some considerations about the relevance of natural language to metaethics. (shrink)

The ideal world semantics of standard deontic logic identifies our obligations with how we would act in an ideal world. However, to act as if one lived in an ideal world is bad moral advice, associated with wishful thinking rather than well-considered moral deliberation. Ideal world semantics gives rise to implausible logical principles, and the metaphysical arguments that have been put forward in its favour turn out to be based on a too limited view of truth-functional representation. It is argued (...) that ideal world semantics should be given up in favour of other, more plausible uses of possible worlds for modelling normative subject-matter. (shrink)

This volume consists of the invited papers presented at the 23rd International Wittgenstein Conference held in Kirchberg, Austria in August 2000. Among the topics treated are: truth, psychologism, science, the nature of rational discourse, practical reason, contextualism, vagueness, types of rationality, the rationality of religious belief, and Wittgenstein. Questions addressed include: Is rationality tied to special sorts of contexts? ls rationality tied to language? Is scientific rationality the only kind of rationality? Is there something like a Western rationality? and: Could (...) we genetically engineer human beings to be less wicked? (shrink)

Overview of fundamental work in deontic logic.

This paper offers a two dimensional variation of Standard Deontic Logic SDL, which we call 2SDL. Using 2SDL we can show that we can overcome many of the difficulties that SDL has in representing linguistic sets of Contrary-to-Duties (known as paradoxes) including the Chisholm, Ross, Good Samaritan and Forrester paradoxes. We note that many dimensional logics have been around since 1947, and so 2SDL could have been presented already in the 1970s. Better late than never! As a detailed case study (...) illustrating the power of 2SDL, we examine the system DL of Deontic Logic of Andrew Jones and Ingmar Pörn offered in 1985 to solve the Chisholm paradox of Contrary to Duties. The critical examination is done using logics and methods available in 1985 and solutions are proposed using what was available in 1985. (shrink)

This paper argues for contrastivism about the deontic modals, 'ought', 'must', and 'may'. A simple contrastivist semantics that predicts the desired entailment relations among these modals is offered.

The thesis aims at developing approaches to transport policy decisions, based on suggestions and ideas originating from moral philosophy and philosophical decision theory. Paper I analyzes the Swedish transport policy goals, and the problem of combining policygoals with welfare economics. A problem of circularity arises as the Swedish transport policygoals are conflicting, and hence must be subject to trade-offs, while several of the goals themselves entail statements on how to prioritize or restrain goals in case of conflict. Paper II analyzes (...) rationality in road safety policy. Problematic features are identified and discussed. The paper argues that the Swedish road safety goal is rational, since it is actionguiding and achievement-inducing. Paper III includes a model of rational choice under risk with biased risk perception. Under certain plausible conditions, a regulator should raise the population’s risk exposure. By deteriorating the environment the regulator can motivate drivers to choose behaviour that is less biased. Paper IV provides a formal representation of goal systems. The focus is on three properties:consistency, conflict, and coherence. It is argued that consistency is adequately regarded as a property relative to the decision situation or, more specifically, the set of alternatives that the agent faces. Conflict is adequately regarded as a relation over subsets of a given goal systemand should likewise be regarded as relative to the set of alternative that the agent faces. Coherence is given a probabilistic interpretation, based on a support relation over subsets of goal systems. Paper V investigates problems associated with standard deontic logic. A deontic predicate is derived, which avoids some of the major paradoxes in the area. In particular, paradoxes occurring when one obligation is derived by logical necessity from another obligation are dealt with. (shrink)

According to typical ought-implies-can principles, if you have an obligation to vaccinate me tomorrow, then you can vaccinate me tomorrow. Such principles are uninformative about conditional obligations: what if you only have an obligation to vaccinate me tomorrow if you synthesize a vaccine today? Then maybe you cannot vaccinate me tomorrow ; what you can do instead, I propose, is make it the case that the conditional obligation is not violated. More generally, I propose the ought-implies-can-obey principle: an agent has (...) an obligation only at times at which the agent can obey the obligation. I also propose another principle, which captures the idea that ‘ought’ implies ‘can avoid’. I defend both principles mainly by arguing that they help explain why agents lose obligations, including conditional ones. (shrink)

The concept of hypodox is dual to the concept of paradox. Whereas a paradox is incompatibly overdetermined, a hypodox is underdetermined. Indeed, many particular paradoxes have dual hypodoxes. So, naively the dual of Russell’s Paradox is whether the set of all sets that are members of themselves is self-membered. The dual of the Liar Paradox is the Truth-teller, and a hypodoxical dual of the Heterological paradox is whether ‘autological’ is autological. I provide some analysis of the duality and I search (...) for modal hypodoxes as duals to known paradoxes. I also try to continue this search further by mapping the relations between some paradoxes and hypodoxes in duality squares. This investigation increases the known extension of the concept of hypodox, and the duality relation between paradoxes and hypodoxes assists in finding some of these. (shrink)

In this paper I argue that deontic modals are hyperintensional, i.e. logically equivalent contents cannot be substituted in their scope. I give two arguments, one deductive and the other abductive. First, I show that the contrary thesis leads to falsity; second, I argue that a hyperintensional theory of deontic modals fares better than its rivals in terms of elegance, theoretical simplicity and explanatory power. I then propose a philosophical analysis of this thesis and outline some consequences. In Section 1 I (...) introduce and define deontic modality and hyperintensionality. In Section 2 I give a reductio for the hyperintensionality of deontic modals. If the argument is sound, a useful corollary is that deontic modals are also non-intensional, and therefore possible-world semantics accounts are illfitted for them. I then show how the main result can be strengthened or weakened by varying the definition of logical validity. In Section 3 I give an abductive argument for the hyperintensionality of deontic modals, arguing that with a single move we are able to solve many paradoxes and puzzles traditionally troubling deontic logic. I present a version of a hyperintensional deontic logic in an appendix, which I prove is sound and complete with respect to a version of truthmaker semantics. (shrink)

This paper focuses on the interaction of reasons and argues that reasons for an action may transmit to the necessary means of that action. Analyzing exactly how this phenomenon may be captured by principles governing normative transmission has proved an intricate task in recent years. In this paper, I assess three formulations focusing on normative transmission and necessary means: Ought Necessity, Strong Necessity, and Weak Necessity. My focus is on responding to two of the main objections raised against normative transmission (...) for necessary means, in that they seem to give us reasons for buying tickets to plays we have no intention of seeing and that the principles give us the wrong result when the means are necessary but not sufficient. Even though these objections have been discussed previously, the counterarguments have so far relied on rejecting premises that the proponents of these objections are unlikely to concede. In this paper, I show how we may answer the objections in a way more likely to convince proponents of the objections. The result is an argument for a key aspect when it comes to understanding how reasons and ends-means normativity function. Normative transmission from ends to necessary means is not only interesting at the structural level, it is also possible to argue that it has implications for areas as diverse as philosophy of rationality, political philosophy and applied ethics. (shrink)

In this paper, I apply the "conceptual role semantics" approach that I have proposed elsewhere (according to which the meaning of normative terms is given by their role in practical reasoning or deliberation) to the meaning of the term 'ought'. I argue that this approach can do three things: It can give an adequate explanation of the special connection that normative judgments have to practical reasoning and motivation for action. It can give an adequate account of why the central principles (...) of deontic logic are correct. It can give an explanation of the precise ways in which the term 'ought' is systematically context-sensitive, so that the term expresses different (but systematically related) concepts in different contexts. (shrink)

This paper offers a two dimensional variation of Standard Deontic Logic SDL, which we call 2SDL. Using 2SDL we can show that we can overcome many of the difficulties that SDL has in representing linguistic sets of Contrary-to-Duties (known as paradoxes) including the Chisholm, Ross, Good Samaritan and Forrester paradoxes. We note that many dimensional logics have been around since 1947, and so 2SDL could have been presented already in the 1970s. Better late than never! As a detailed case study (...) illustrating the power of 2SDL, we examine the system DL of Deontic Logic of Andrew Jones and Ingmar Pörn offered in 1985 to solve the Chisholm paradox of Contrary to Duties. The critical examination is done using logics and methods available in 1985 and solutions are proposed using what was available in 1985. (shrink)

Standard deontic logic (SDL) is defined on the basis of possible world semantics and is a logic of alethic-deontic modalities rather than deontic modalities alone. The interpretation of the concepts of obligation and permission comes down exclusively to the logical value that a sentence adopts for the accessible deontic alternatives. Here, we set forth a different approach, this being a logic which additionally takes into consideration whether sentences stand in relation to the normative system or to the system of values (...) under which we predicate the deontic qualifications. By taking this aspect into account, we arrive at a logical system which preserves laws proper to a deontic logic but where the standard paradoxes of deontic logic do not arise. It is a logic of strictly-deontic modalities DR. (shrink)

Monomodal logic has exactly two maximally normal logics, which are also the only quasi-normal logics that are Post complete, and they are complete for validity in Kripke frames. Here we show that addition of a propositional constant to monomodal logic allows the construction of continuum many maximally normal logics that are not valid in any Kripke frame, or even in any complete modal algebra. We also construct continuum many quasi-normal Post complete logics that are not normal. The set of extensions (...) of S4.3 is radically altered by the addition of a constant: we use it to construct continuum many such normal extensions of S4.3, and continuum many non-normal ones, none of which have the finite model property. But for logics with weakly transitive frames there are only eight maximally normal ones, of which five extend K4 and three extend S4. (shrink)

RESUMO De acordo com a teoria das funções de verdade, a verdade/falsidade de uma proposição é computável a partir da verdade/falsidade das suas proposições “internas”: para cada proposição há uma função entre valores de verdade. Aplicada a proposições modais, origina a semântica dos mundos possíveis e, aplicada a proposições normativas, origina uma semântica que reduz os conceitos normativos aos conceitos modais, a semântica modal. Esta redução fica posta em questão com a existência dos chamados ‘paradoxos da lógica deôntica’. Estes não (...) podem ser vistos como meras anomalias, mas devem ser vistos como indícios da incorreção da semântica modal. Em todos eles, a regra da necessitação, assim como o axioma da distribuição, “não batem certo”. Não obstante, o cumprimento/incumprimento das normas já é computável a partir da verdade/falsidade das proposições que expressam os estados de coisas devidos. ABSTRACT According to the theory of truth-functions the truth/falsehood of a proposition is computable from the truth/falsehood of its “internal” propositions: for each proposition there is a function between truth values. Possible world semantics arises from the application of that theory to modal propositions; modal semantics - the reduction of normative concepts to modal concepts - arises from its application to normative propositions. But the ‘paradoxes of deontic logic’, as they are called, undermine such reduction: they cannot be seen as mere anomalies but instead as evidence for the wrongness of modal semantics. In all these paradoxes, the necessitation rule, as well as the distribution axiom, fail. Nevertheless, the fulfillment/nonfulfillment of norms is computable from the truth/falsehood of the propositions which express the required states of affairs. (shrink)

Formalising deontic concepts, such as obligation, prohibition and permission, is normally carried out in a modal logic with a possible world semantics, in which some worlds are better than others. The main focus in these logics is on inferring logical consequences, for example inferring that the obligation O q is a logical consequence of the obligations O p and O. In this paper we propose a non-modal approach in which obligations are preferred ways of satisfying goals expressed in first-order logic. (...) To say that p is obligatory, but may be violated, resulting in a less than ideal situation s, means that the task is to satisfy the goal p ∨ s, and that models in which p is true are preferred to models in which s is true. Whereas, in modal logic, the preference relation between possible worlds is part of the semantics of the logic, in this non-modal approach, the preference relation between first-order models is external to the logic. Although our main focus is on satisfying goals, we also formulate a notion of logical consequence, which is comparable to the notion of logical consequence in modal deontic logic. In this formalisation, an obligation O p is a logical consequence of goals G, when p is true in all best models of G. We show how this non-modal approach to the treatment of deontic concepts deals with problems of contrary-to-duty obligations and normative conflicts, and argue that the approach is useful for many other applications, including abductive explanations, defeasible reasoning, combinatorial optimisation, and reactive systems of the production system variety. (shrink)

Monomodal logic has exactly two maximally normal logics, which are also the only quasi-normal logics that are Post complete, and they are complete for validity in Kripke frames. Here we show that addition of a propositional constant to monomodal logic allows the construction of continuum many maximally normal logics that are not valid in any Kripke frame, or even in any complete modal algebra. We also construct continuum many quasi-normal Post complete logics that are not normal. The set of extensions (...) of S4.3 is radically altered by the addition of a constant: we use it to construct continuum many such normal extensions of S4.3, and continuum many non-normal ones, none of which have the finite model property. But for logics with weakly transitive frames there are only eight maximally normal ones, of which five extend K4 and three extend S4. (shrink)

Standard dyadic deontic logic (as well as standard deontic logic) has recently come under attack by moral philosophers who maintain that the axioms of standard dyadic deontic logic are biased against moral theories which generate moral conflicts. Since moral theories which generate conflicts are at least logically tenable, it is argued, standard dyadic deontic logic should be modified so that the set of logically possible moral theories includes those which generate such conflicts. I argue that (1) there are only certain (...) types of moral conflicts which are interesting, and which have worried moral theorists, (2) the modification of standard dyadic deontic logic along the lines suggested by those who defend the possibility of moral conflicts makes possible only uninteresting types of moral conflicts, and (3) the general strategy of piecemeal modification standard dyadic deontic logic is misguided: the possibility of interesting moral conflicts cannot be achieved in that way. (shrink)