(See also the separate entry for the volume itself.) This introduction has three parts. The first providing an overview of some main lines of research in deontic logic: the emergence of SDL, Chisholm's paradox and the development of dyadic deontic logics, various other puzzles/challenges and areas of development, along with philosophical applications. The second part focus on some actual and potential fruitful interactions between deontic logic, computer science and artificial intelligence. These include applications of deontic logic to AI knowledge representation (...) in legal systems, to modelling computer systems where it is expected that sub-ideal states will emerge and require countermeasures, to norm-governed human interactions with computer systems, and to the representation of some features of multi-agent systems where different agent-like computer systems interact with one another. The third and final part briefly groups and previews the papers in the anthology. (shrink)

This paper provides an analysis of contrary-to-duty reasoning from the proof-theoretical perspective of category theory. While Chisholm’s paradox hints at the need of dyadic deontic logic by showing that monadic deontic logics are not able to adequately model conditional obligations and contrary-to-duties, other arguments can be objected to dyadic approaches in favor of non-monotonic foundations. We show that all these objections can be answered at one fell swoop by modeling conditional obligations within a deductive system defined as an instance of (...) a symmetric monoidal closed category. Using category theory as a foundational framework for logic, we show that it is possible to model conditional normative reasoning and conflicting obligations within a monadic approach without adding further operators or considering deontic conditionals as primitive. (shrink)

In this paper, I will discuss some examples of the so-called contrary-to-duty paradox, a well-known puzzle in deontic logic. A contrary-to-duty obligation is an obligation telling us what ought to be the case if something forbidden is true, for example: ‘If she is guilty, she should confess’. Contrary-to-duty obligations are important in our moral and legal thinking. Therefore, we want to be able to find an adequate symbolisation of such obligations in some logical system, a task that has turned out (...) to be difficult. This is shown by the so-called contrary-to-duty paradox. I will investigate and evaluate one kind of solution to this problem that has been suggested in the literature, which I will call the ‘counterfactual solution’. I will use some recent systems that combine not only counterfactual logic and deontic logic, but also temporal logic, in my analysis of the paradox. I will argue that the counterfactual solution has many attractive features and that it can give a fairly satisfactory answer to some examples of the contrary-to-duty paradox, but that it nevertheless has some serious problems. The conclusion is that, notwithstanding the many attractive features of the solution, there seem to be other approaches to the paradox that are more promising. (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)

The main contribution of this paper is a completeness result for an axiomatization of Hansson [13]'s deontic system DSDL2, whose semantics involves a non-necessarily transitive betterness relation. Reference is made to a deductive system put forth by Åqvist [2, 3].

James E. Tomberlin [6] has recently argued that the logical systems of conditional obligation proposed by Azizah al-Hibri [1] and Peter Mott [5] are incapable of resolving at least one variant of the notorious contrary to duty imperative paradox, formulated originally by Chisholm [2]. Tomberlin concedes that these systems offer the very best of the' “conditional obligation approach” to deontic logic and concludes his critical discussion with the pessimistic remark that “the best of this approach is simply not good enough. (...) Deontic logic … is obliged to turn elsewhere for its proper formulation and resolution of the deontic paradoxes”. Below I argue that Tomberlin's three central arguments against al-Hibri and Mott are fallacious. (shrink)

Suppose that John has a moral obligation to stop smoking given that smoking is dangerous to his health. Suppose further that smoking is dangerous to his health. Does it follow that John has a moral obligation to stop smoking? Although intuition inclines one to answer in the affirmative, recent developments in deontic logic apparently call this inference into question. The issue at hand is whether unconditional obligations are detachable from conditional obligations on the basis of purely factual considerations. I believe (...) that they are not. In the course of arguing for this position I defend a novel restricted rule of detachment which is constructed out of both factual and normative components. (shrink)