Fictionalism in metaphysics

Fictionalism proposes that a certain discourse – such as talk about possible worlds, or mathematical talk – is useful, perhaps even indispensable for theoretical purposes, but should not be taken as true. The fictionalist argues that the content of this discourse can be treated as fictional – as belonging to ‘the fiction of many possible worlds’ or ‘the fiction of numbers as objects’, for example. By adopting this treatment, they propose that we can have the benefits which are offered by positing entities such as worlds, without believing in them. In this way, fictionalism tries to offer a way in which we can engage in and make sense of the same kind of talk a realist licenses, but without the realist’s metaphysical commitments. ‘Fictionalism’ is a term of art, and its boundaries with neighbouring positions such as quasi-realism, error theory and deflationism are not always clear-cut, but a distinctive idea fictionalism brings to metaphysics is that we might make sense of an area of discourse by giving a realist account the status of fiction.

One way some fictionalists account for an area of discourse in fictionalist terms is by making use of fiction operators such as ‘It is true in the many-worlds fiction that …’ or ‘According to the fiction of numbers as objects …’ Another way is by suggesting that participating in such discourse could be something done in a spirit of pretence: what the realist suggests would be explained by believing in certain objects or taking certain statements to be true can, the fictionalist suggests, be explained by construing the discourse as something more like a game of make-believe in which we imagine certain objects to exist and certain facts to obtain.

Some challenges for fictionalism stem from the nature of fiction itself. For example, fictional characters, or fictions themselves, might be best understood as abstract objects, but some fictionalists want to avoid committing to abstract entities. Fictions can also be unlike the discourses fictionalists wish to capture, in certain significant ways. Other potential problems for fictionalism include a threat that it is self-defeating, some difficulties with characterizing what the content of the fiction is, and a challenge that philosophers do not know best concerning the commitments of other people’s discourse.