ABSTRACT
Moral realism is the position that there are moral facts or truths which do not depend for their existence on the various ways in which people learn of, believe, or justify those facts or truths. If it is a fact that they should not commit murder, the moral realist believes that the fact would stay the same however their attitudes and beliefs toward murder might change. People need to show that the new method does not reduce to possible world semantics nonrealistically interpreted. They have to adopt a modal realist account of possible worlds to explain the opacity of modal and counterfactual statements. Even if a possible world is only a state description in this world, they can explain the opacity of It is possible that a monster lives in that loch. Giving up moral realism is therefore not a promising way of meeting the challenge which the author have posed in this chapter.
