Recent work on the development of a dialogical approach to the logic of fi ction stresses the notion of existence as choice. Moreover, this approach to existence has been combined with the notion of ontological dependence as deployed by A. Thomasson's artifactual theory of fi ction. In order to implement such a combination within the dialogical frame several predicates of ontological dependence have been defi ned. However, the defi nition of such predicates seems to lean on a model-theoretic semantics for modal logic after all. The main aim of the present paper is to set a dialogical frame for the study of fi ctions in the context of the dialogical approach of CTT recently developed by S. Rahman and N. Clerbout where a fully-interpreted language is unfolded. We will herewith develop the idea that in such a setting fi ctional entities are understood as hypothetical objects, that is, objects (functions) the existence of which is dependent upon one or more hypotheses that restrict the scope of choices available. We will fi nish the paper by suggesting that this provides both a natural and genuinely dialogical way to understand R. Frigg's take on scientifi c models as fi ctions and a new perspective on Thomasson's notion of generic ontological dependence.Keywords: fi ction, dialogues, dialogical logic, hypothetical objects, scientifi c models.
ResumoTrabalhos recentes sobre o desenvolvimento de uma abordagem dialógica para a lógica da fi cção enfatizam a noção de existência como escolha. Além disso, 1 The present work is a result of the project Fondecyt Regular No. 1141260 (Principal Investigator: Juan Redmond). We thank the CONICYT (Chile) for fostering the preparation of this article and Nicolas Clerbout (University of Valparaíso, Convenio de Desempeño CDHACS, Instituto de Filosofía), for fruitful discussions during and after the meetings that took place within the frame of the project.
IntroductionA brief examination of the most recent literature in logic will make it apparent that a host of research in this area is devoted to the study of the interface between games, logic and epistemology. These studies provide the basis of ongoing enquiries into the history and philosophy of logic, going from the Indian, the Greek, the Arabic, the Obligationes of the Middle Ages to the most contemporary developments in the fields of theoretical computer science, computational linguistics, artificial intelligence, social sciences and legal reasoning. In fact, a dynamic turn, as J. v. Benthem puts it, is taking place where the epistemic aspects of inference are linked with game theoretical approaches to meaning 4 . In regard to the birth of this turn, it could be placed around the 1960s, when P. Lorenzen and K. Lorenz developed dialogical logic -inspired by Wittgenstein's language games and mathematical game theory -and when some time later Hintikka (1962Hintikka ( , 1973 combined game-theoretical semantics with epistemic (modal) logic 5 . However, while Hintikka's approach is based on a model theoretic semantics, ...