For this reason, they address van Fraassen’s allegations against IBE qua justification of the existence of unobservable entities in a couple of pages and prefer focusing on the other lines they identified. ) no relevance to the scientific practice. Minikoski and Rodrigues da Silva consider that the distinction is of (. The first one, put forward by the Dutch philosopher in his seminal book The Scientific Image (1980), concerns the distinction between observable and unobservable entities. In a recent work published in this journal, “Van Fraassen e a inferência da melhor explicação” (2016), Minikoski and Rodrigues da Silva identify four critical lines proposed by Bas van Fraassen against the form of abductive reasoning known as ‘inference to the best explanation’ (IBE). On the negative side, even under the weaker precisification of (a), I establish that (3) certain finite theories cannot be nominalized by a finite theory. On the positive side, even under the stronger precisification of (a), I establish that (1) if the vocabulary of T is finite, a nominalizing theory can always be found that is recursive if T is, and (2) if T postulates infinitely many δ:s, a nominalizing theory can always be found that is no more computationally complex than T. In particular, I note that condition (a) can be understood either in terms of syntactic or semantic equivalence, where the latter is strictly stronger than the former.
In an attempt to refute the realist claim, I try to solve the general problem of nominalizing T (with respect to δ), namely to find a theory T′ satisfying conditions (a)–(c) under various precisifications thereof. ) (c) T′ is at least as attractive as T in terms of other theoretical virtues.
Motivated by the meta-ontology of Quine, I take this claim to imply that, for some first-order theory T and formula δ(x) such that T ⊢ ∃xδ ∧ ∃x¬δ, where δ(x) is intended to apply to all and only empirical entities, there is no first-order theory T′ such that (a) T and T′ describe the δ:s in the same way, (b) T′ ⊢ ∀xδ, and (. Some realists claim that theoretical entities like numbers and electrons are indispensable for describing the empirical world.