Online research in philosophy

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.

Hilary Putnam has famously argued that we can know that we are not brains in a vat because the hypothesis that we are is self-refuting.1 While Putnam’s argument has generated interest primarily as a novel response to skepticism, his original use of the brain in a vat scenario was meant to illustrate a point about the “mind/world relationship.”2 In particular, he intended it to be part of an argument against the coherence of metaphysical realism, and thus to be part of a defense of his conception of truth as idealized rational acceptability. Putnam’s argument has drawn a good deal of criticism already, but it will be argued here that these criticisms fail to capture the central problem with Putnam’s argument. Putnam’s conclusions about the self refuting character of the brain in a vat hypothesis, rather than simply being a consequence of his semantic externalism, will be shown to be actually out of line with central and plausible aspects of his own account of the relationship between our minds and the world. Reflections on intentionality and semantics ultimately give us no compelling reason to suppose that the beliefs expressed by claims like “I am a brain in a vat” could not be true,3 but (pace Putnam) this supports neither skepticism nor metaphysical realism.

In this paper we offer an exegesis of Hilary Putnam’s classic argument against the brain-in-avat hypothesis offered in his Reason, truth and history (1981). In it, Putnam argues that we cannot be brains in a vat because the semantics of the situation make it incoherent for anyone to wonder whether they are a brain a vat. Putnam’s argument is that in order for ‘I am a brain in a vat’ to be true, the person uttering it would have to be able to refer successfully to those things: the vat, and the envatted brain. Putnam thinks that reference can’t be secured without relevant kinds of causal relations, which, if envatted, the brain would lack, and so, it fails to be able to meaningfully utter ‘I am a brain in a vat’. We consider the implications of Putnam’s arguments for the traditional sceptic. In conclusion, we discuss the role of Putnam’s arguments against the brain in a vat hypothesis in his larger defense of his own internal realism against metaphysical realism.

Putnam presents a Peircean characterization of truth in an attempt to avoid relativism, which he argues is incoherent. I argue that Putnam has not avoided relativism. According to Putnam's theory of understanding, we must understand all claims concerning a Peircean community in terms of our own experiences and in terms of our own standards of rational assertability. Truth simply collapses into warranted assertability. At this point Putnam appeals to the objectivity of our standards of assertability. But Putnam's notion of "objectivity for us" is a notion of objectivity which the relativist can happily adopt. Putnam's failure to provide more than a superficial distinction between internal realism and relativism means that internal realism faces the same problems which Putnam directs at "self-refuting" relativism.

Hilary Putnam deals in this book with some of the most fundamental persistent problems in philosophy: the nature of truth, knowledge and rationality. His aim is to break down the fixed categories of thought which have always appeared to define and constrain the permissible solutions to these problems.

Hilary Putnam and Nelson Goodman are two of the twentieth century's most persuasive critics of metaphysical realism, however they disagree about the consequences of rejecting metaphysical realism. Goodman defended a view he called irrealism in which minds literally make worlds, and Putnam has sought to find a middle path between metaphysical realism and irrealism. I argue that Putnam's middle path turns out to be very elusive and defend a dichotomy between metaphysical realism and irrealism.

Putnam's internal realism entails the simultaneous rejection of metaphysical realism and (anything goes or total or cultural) relativism. Putnam argues, in some places, that relativism is self-contradictory, and in others, that it is self-refuting. This paper attempts the exegetical task of explicating these challenging arguments, and the critical task of suggesting that a full-blown epistemological relativism may be capable of surviving the Putnam attack.

This is the third volume of Hilary Putnam's philosophical papers, published in paperback for the first time. The volume contains his major essays from 1975 to 1982, which reveal a large shift in emphasis in the 'realist'_position developed in his earlier work. While not renouncing those views, Professor Putnam has continued to explore their epistemological consequences and conceptual history. He now, crucially, sees theories of truth and of meaning that derive from a firm notion of reference as inadequate.