Abstract

Some fictionalist approaches to the notion of scientific model are based on the concept of game of make-believe developed by Kendall Walton, without proposing a similar interpretation of it. The distinction between authorized and unauthorized games can be one of the sources of those divergences. In relation to the distinction made by Walton, the de dicto and de re modalities of the fiction-operator reflect different epistemological engagements concerning objects which satisfy properties. This paper aims at following up on the proposals formulated by Roman Frigg and Adam Toon by using some modal logic concepts, notably by defining the identities of properties in modal contexts in terms of world-lines. Applying a model to a target-system consists in transposing fictional truths into actual situations, through an extrapolation that goes beyond the games of make-believe.