Online research in philosophy

In an earlier paper, I claimed that one version of Putnam's model-theoretic argument against realism turned on a subtle, but philosophically significant, mathematical mistake. Recently, Luca Bellotti has criticized my argument for this claim. This paper responds to Bellotti's criticisms.

In "Realism and Reason" Hilary Putnam has offered an apparently strong argument that the position of metaphysical realism provides an incoherent model of the relation of a correct scientific theory to the world. However, although Putnam's attack upon the notion of the "intended" interpretation of a scientific theory is sound, it is shown here that realism may be formulated in such a way that the realist need make no appeal to any "intended" interpretation of such a theory. Consequently, it can be shown that realism is immune to Putnam's criticism and that attempts at reformulating this criticism are not likely to meet with success.

I present two generalizations of Putnam's model-theoretic argument against realism. The first replaces Putnam's model theory with some new, and substantially simpler, model theory, while the second replaces Putnam's model theory with some more accessible results from astronomy. By design, both of these new arguments fail. But the similarities between these new arguments and Putnam's original arguments illuminate the latter's overall structure, and the flaws in these new arguments highlight the corresponding flaws in Putnam's arguments.

Putnam famously attempted to use model theory to draw metaphysical conclusions. His Skolemisation argument sought to show metaphysical realists that their favourite theories have countable models. His permutation argument sought to show that they have permuted models. His constructivisation argument sought to show that any empirical evidence is compatible with the Axiom of Constructibility. Here, I examine the metamathematics of all three model-theoretic arguments, and I argue against Bays (2001, 2007) that Putnam is largely immune to metamathematical challenges.

A variant of Hilary Putnam's model-theoretic argument against metaphysical realism appears to show that our quantifiers do not determinately range over absolutely everything. This paper argues that some recent attempts to respond to the quantificational skeptic are unsuccessful and offers an alternative response: the key to answering the skeptic is not to refute her argument but to realize that the argument's setup prevents it from being convincing to those it is directed at.

Bas van Fraassen has recently argued for a "dissolution" of Hilary Putnam's well-known model-theoretic argument. In this paper I argue that, as it stands, van Fraassen's reply to Putnam is unsuccessful. Nonetheless, it suggests the form a successful response might take.

Igor Douven has offered an original reconstruction and defence of Putnam's model-theoretic argument against metaphysical realism. Douven's construal has notable exegetical virtues, since it makes sense of some assumptions in Putnam's argument which his opponents have considered question-begging or puzzling. In this article I provide an indirect defence of metaphysical realism, by showing why this new version of the anti-realist argument should also be rejected. The main problems in the Douven-Putnam argument come from ascribing to the realist a distorted view of correspondence truth. The view entails that when no feature selects just one of all the possible interpretations of language (the relations of reference between the terms and the world) the existence of an interpretation suffices to make true a (consistent) theory. The sensible realist is not committed to this extreme conception of correspondence truth. /// Igor Douven ha presentado y defendido una reconstructión del argumento teórico-modelista de Putnam contra el realismo metafísico. Esta versión tiene ciertas virtudes exegéticas, pues hace inteligible algunos presu- puestos putnamianos que sus críticos han considerado injustificados o sorprendentes. En este artículo proporciono una defensa indirecta del realismo metafisico, mostrando por qué debe también rechazarse el argumento antirrealista bajo esta nueva forma. Los problemas principales del argumento Douven-Putnam proceden de atribuir al realista una concepción distorsionada de la idea de verdad como correspondencia. Conforme a esa concepción, la ausencia de factores que seleccionen una única interpretación del lenguaje de entre las muchas posibles (una relación de referenda entre los términos y el mundo) conlleva que la existencia de alguna interpretación ya es suficiente para hacer verdadera a una teoría que sea consistente. El realista sensato no está obligado a aceptar esa tesis.

Two of Hilary Putnam's model-theoretic arguments against metaphysical realism are examined in detail. One of them is developed as an extension of a model-theoretic argument against mathematical realism based on considerations concerning the so-called Skolem-Paradox in set theory. This argument against mathematical realism is also treated explicitly. The article concentrates on the fine structure of the arguments because most commentators have concentrated on the major premisses of Putnam's argument and especially on his treatment of metaphysical realism. It is shown that the validity of Putnam's arguments is doubtful and that realists are by no means forced to accept the theses Putnam ascribes to them. It is concluded that Putnam fails to give convincing arguments for rejecting mathematical or metaphysical realism. Furthermore, Putnam's internal realism is discussed critically.