Zasada aglomeracji i dylematy moralne

A Deontic Logic for Normative DilemmasAbstract: Standard deontic logic does not tolerate normative conflicts. If we assume that one ought to do A and ought to do B, but cannot do them both, we get a contradiction within deontic logic. Philosophers who deny that there could be genuine moral dilemmas treat this fact as the proof that dilemmas are logically impossible. At the same time, the advocates of the possibility of moral dilemmas propose to reject or restrict standard deontic principles. What consequences does it have for the resulting logic? Some of them are too strong because they contain the theorem of normative triviality or “deontic explosion,” which says that if there is any case of normative conflict, then everything is obligatory. On the other hand, some of them are too weak, since they are not able to validate more important deontic inferences especially the Smith Argument. Lou Goble introduces three criteria of adequacy that any deontic logic should meet if it is to accommodate normative conflicts successfully. First, I present these conditions and then I introduce a new logic of ought that fully meets all of them.

Reasoning About Prescription and Description Using Prioritized Default Rules

In this paper we introduce a prioritized default logic. We build this logic modularly from Standard Deontic Logic by the addition of default rules and priorities among them. Our main aim is to provide a logical framework to reason about scenarios where prescriptive and descriptive statements coexist and may be incomplete and contradictory. We motivate and illustrate the technical elements of our work with the use of examples (classical, and coming from software engineering). In addition, we present sound, complete, and terminating (with loop check) tableau-based proof calculi for credulous and sceptical reasoning in our logic.

Omega-inconsistency without cuts and nonstandard models

This paper concerns the relationship between transitivity of entailment, omega-inconsistency and nonstandard models of arithmetic. First, it provides a cut-free sequent calculus for non-transitive logic of truth STT based on Robinson Arithmetic and shows that this logic is omega-inconsistent. It then identifies the conditions in McGee (1985) for an omega-inconsistent logic as quantified standard deontic logic, presents a cut-free labelled sequent calculus for quantified standard deontic logic based on Robinson Arithmetic where the deontic modality is treated as a predicate, proves omega-inconsistency and shows thus, pace Cobreros et al.(2013), that the result in McGee (1985) does not rely on transitivity. Finally, it also explains why the omega-inconsistent logics of truth in question do not require nonstandard models of arithmetic.

Czeżowski's Axiological Concepts as Full-Fledged Modalities.

This short paper provides a tentative formalization of Czeżowski's ideas about axiological concepts: Good and Evil are conceived of as modalities rather than as predicates. A natural account of the resulting “ethical logic” appears to be very close to standard deontic logic. If one does not resolve to become an antirealist regarding moral values, a possible way out is to become a revisionist about deontology: convert to intuitionism or some other kind of revisionism in deontic logic, and remain classical in ethical logic.

Reply to “Forrester's Paradox”

Forrester claims to have shown that a contradiction can be derived from a set of two apparently innocuous moral (or legal) rules together with standard deontic logic (SDL), a principle for adverbial detachment, and a statement of fact. Let l be a system of laws that has the following as immediate consequences:(1) It is obligatory* that Smith not murder Jones.(2) It is obligatory; that, if Smith murders Jones, then Smith murders Jones gently.