ABSTRACT
The author found that a major principle of standard deontic logic (SDL) semantics is dubious. He noted that problems with circularity and with the accessibility relation makes it doubtful whether deontic semantics and deontic logic can ever be of use to people. He considers the effect of these three problems on some standard objections to deontic logic, including such puzzles as the Good Samaritan paradox and Chisholm's contrary-to-duty paradox. For similar reasons, if we introduce into SDL semantics the changing worlds of Rantala's urn models, people avoid some but not all the difficulties raised by Chisholm's paradox. They introduces the notion of causal laws and branching worlds into urn models. But, as he has argued, SDL semantics is so beset with epistemic problems that they cannot make a practical use of it. He also argues that SDLT5 and SDLT1 would be just about the only survivors among the principles of deontic logic, People deprive SDL semantics of backward translation.
