Fictionalism is a methodological theory in philosophy that suggests that statements of a certain sort should not be taken to be literally true, but merely as a useful fiction. Two important strands of fictionalism are modal fictionalism (which states that possible worlds, regardless of whether they exist or not, may be a part of a useful discourse) and mathematical fictionalism, which states that talk of numbers and other mathematical objects is nothing more than a convenience for doing science. Also in meta-ethics, there is an equivalent position called moral fictionalism.
Fictionalism consists in at least the following three theses:
Claims made within the domain of discourse are taken to be truth-apt; that is, true or false.
The domain of discourse is to be interpreted at face value--not reduced to meaning something else.
The aim of discourse in any given domain is not truth, but some other virtue(s) (e.g., simplicity, explanatory scope).
