Irrelevant Alternatives and Frankfurt Counterfactuals

In rejecting the Principle of AlternatePossibilities (PAP), Harry Frankfurt makes useof a special sort of counterfactual of thefollowing form: ``he wouldn't have doneotherwise even if he could have'. Recently,other philosophers (e.g., Susan Hurley (1999,2003) and Michael Zimmerman (2002)) haveappealed to a special class of counterfactualsof this same general form in defending thecompatibility of determinism andresponsibility. In particular, they claim thatit can be true of agents that even if they aredetermined, and so cannot do otherwise, theywouldn't have done otherwise even if they couldhave. Using as a central case an argument ofSusan Hurley's, I point out that thecounterfactuals in question are both``interlegal' and ``indeterministic', and I raisedoubts about whether this special class ofcounterfactuals have clear truth conditions. Finally I suggest that acknowledging thesepoints leads to an appreciation of the realstrength of Frankfurt-style examples.