In a first part, I defend that formal semantics can be used as a guide to ontological commitment. Thus, if one endorses an ontological view \(O\) and wants to interpret a formal language \(L\) , a thorough understanding of the relation between semantics and ontology will help us to construct a semantics for \(L\) in such a way that its ontological commitment will be in perfect accordance with \(O\) . Basically, that is what I call constructing formal semantics from an (...) ontological perspective. In the rest of the paper, I develop rigorously and put into practice such a method, especially concerning the interpretation of second-order quantification. I will define the notion of ontological framework: it is a set-theoretical structure from which one can construct semantics whose ontological commitments correspond exactly to a given ontological view. I will define five ontological frameworks corresponding respectively to: (i) predicate nominalism, (ii) resemblance nominalism, (iii) armstrongian realism, (iv) platonic realism, and (v) tropism. From those different frameworks, I will construct different semantics for first-order and second-order languages. Notably I will present different kinds of nominalist semantics for second-order languages, showing thus that we can perfectly quantify over properties and relations while being ontologically committed only to individuals. I will show in what extent those semantics differ from each other; it will make clear how the disagreements between the ontological views extend from ontology to logic, and thus why endorsing an ontological view should have an impact on the kind of logic one should use. (shrink)

Modal Meinongianism is a form of Meinongianism whose main supporters are Graham Priest and Francesco Berto. The main idea of modal Meinongianism is to restrict the logical deviance of Meinongian non-existent objects to impossible worlds and thus prevent it from “contaminating” the actual world: the round square is round and not round, but not in the actual world, only in an impossible world. In the actual world, supposedly, no contradiction is true. I will show that Priest’s semantics, as originally formulated (...) in Towards Non-being, tell us something different. According to certain models, there are true contradictions in the actual world. Berto and Priest have noticed this unexpected consequence and have suggested a solution, but I will show that their solution is highly questionable. In the last section of this paper, I will introduce a new and simpler version of modal Meinongianism that avoids the problem. (shrink)

Je montrerai en premier lieu comment et pourquoi la sémantique formelle peut être employée comme un outil pour déterminer l’engagement ontologique d’une théorie : je soutiendrai d’une part que la sémantique doit être prise au sérieux comme apte à décrire la vérifaction des formules du langage; d’autre part, que les engagements ontologiques d’une théorie sont déterminés par ses vérifacteurs. De là, j’exposerai une méthode générale permettant, étant donné un certain type d’ontologie, de construire une sémantique dont les engagements ontologiques sont (...) en accord avec celle-ci. Pour cela, je définirai la notion de cadre ontologique : il s’agit d’une structure telle que toute sémantique cons-truite à partir de cette structure aura un certain engagement ontologique déterminé à l’avance. J’exposerai quatre cadres représentant deux types de nominalisme et deux types de réalisme, et j’esquisserai à partir de ces cadres quatre sémantiques pour les langages du premier ordre. (shrink)