The aim of this paper is to argue in favor of the view that some counterpossibles are false. This is done indirectly by showing that accepting the opposite view, i.e., one that ascribes truth to each and every counterpossible, results in the claim that every necessarily false theory has exactly the same consequences. Accordingly, it is shown that taking every counterpossible to be true not only undermines the value of debates over various alternative theories and their consequences, but also puts (...) into question the very possibility of such debates. In order to explicate this thesis, the close bond between counterpossibles and the so-called story prefix is explored. A number of possible responses to this criticism are also presented, and it is argued that none of them address the main problem. (shrink)

The canonical version of possible worlds semantics for story prefixes is due to David Lewis. This paper reassesses Lewis's theory and draws attention to some novel problems for his account.

Modal fictionalists propose to defuse the unwanted ontological commitments of modal realism by treating modal realism as a fictional story, and modal assertions as assertions, prefixed by a fictionalist operator, that something is true in that story. However, consideration of conditionals with modal antecedents raises the problem ofembedding, which shows that the simple prefixing strategy cannotsucceed. A compositional version of the fictionalist strategy isdeveloped and critiqued, and some general semantic morals aredrawn from the failures of both strategies.

Some claim that Composition as Identity (CI) entails Mereological Essentialism (ME). If this is right, then we have an effective modus tollens against CI: ME is clearly false, so CI is, too. Rather than deny the conditional, I will argue that a CI theorist should embrace ME. I endorse a theory of modal parts such that ordinary objects are spatially, temporally, and modally extended. Accepting modal parts is certainly beneficial to CI theorists, but it also provides elegant solutions to the (...) traditional puzzles of constitution, making it a competitive move in its own right. (shrink)

Questions about necessity (or what has to be, or what cannot be otherwise) and possibility (or what can be, or what could be otherwise) are questions about modality. Fictionalism is an approach to theoretical matters in a given area which treats the claims in that area as being in some sense analogous to fictional claims: claims we do not literally accept at face value, but which we nevertheless think serve some useful function. However, despite its name, “Modal Fictionalism” in its (...) usual manifestations is not primarily fictionalism about claims of necessity and possibility, but rather a fictionalist approach to claims about possible worlds. (For instance, modal fictionalism is not normally fictionalist about the claim that “it is possible that there be a species of tail-less kangaroo”, but rather about the claim that “there is a possible world in which there is a species of tail-less kangaroo”.) The practice of taking possible worlds to be merely convenient fictions, or of treating talk about possible worlds as being useful without being literally correct, is quite common in philosophical circles. It is only recently, however, that philosophers have seriously examined the implications of taking possible worlds to be merely fictional objects, like Sherlock Holmes or a frictionless surface. (shrink)

I argue that fictionalism is an unpromising alternative to realism in two important respects. First, fictionalism offers a less satisfactory modal semantics because the incorporated fictive operator is itself modal and its results differ significantly from realism. Second, fictionalism struggles to provide us with a satisfactory account of the ontological grounding of modal truth and finds itself in opposition to several influential accounts of fictional objects which I discuss. I conclude by suggesting that, given the fictionalist’s motivation, a more promising (...) avenue of research would be the older and currently unfashionable fictionalism espoused by Vaihinger (1935). (shrink)

Bob Hale in Hale 1995b posed a dilemma for modal fictionalism (more specifically, Rosen's version of modal fictionalism). A modal fictionalist who maintains the version outlined in Rosen 1990 believes that the fiction of possible worlds (PW, to use Rosen and Hale's abbreviation) is not literally true. The question arises, however, about its modal status. Is it necessarily false, or contingently false? In either case, Hale argues, the modal fictionalist is in trouble. Should the modal fictionalist claim that the story (...) of possible worlds is necessarily false, then the modal fictionalist cannot gloss their "according to the fiction of possible worlds ... ." prefix as "were the fiction of possible worlds true, then ... would be true". This is because, according to Hale, conditional claims with antecedents which are necessarily false are automatically true, so it follows that if the fiction of possible worlds is taken to be necessarily false, all conditionals of the form "were the fiction of possible worlds true then ..." are true, and not merely the ones that the modal fictionalist wishes to endorse. If the modal fiction is to be useful, not everything should be true according to it: examples of claims that had better not be true according to it include the claim that 2+2=7, or the claim that there are no possible worlds. On the other hand, if the fiction of possible worlds (PW) is only contingently false, Hale claims this also lands the Rosen's fictionalism in unacceptable trouble, though it is not so clear why (see below). Let me discuss these horns in turn. (shrink)