Ian Rumfitt

In developing his alternative, Brandom starts from a version of inferential-role semantics according to which an assertion's content is constituted by its place in a field of inferential relations. It is because we have "an independent theoretical grip on the notion of an inference", and of its goodness or badness, that we are able to attain a notion of content that is prior to any of the representational concepts. He stresses that the relevant assessment of inferences is not whether they are logically valid, but whether they are "materially correct," in a sense that Sellars is said to have succeeded in explaining. "As examples, consider the inference from 'Pittsburgh is to the West of Philadelphia' to 'Philadelphia is to the East of Pittsburgh', the inference from 'Today is Wednesday' to 'Tomorrow is Thursday', and that from 'Lightning is seen now' to 'Thunder will be heard soon'. It is the contents of the concepts West and East that make the first a good inference... and the contents of the concepts lightning and thunder, as well as the temporal concepts, that underwrite the third". Subsentential contents are extracted from the sentential contents thereby identified using substitutional methods derived from Frege.

It seems beyond doubt that a thinker can come to know a conclusion by deducing it from premisses that he knows already, but philosophers have found it puzzling how a thinker could acquire knowledge in this way. Assuming a broadly externalist conception of knowledge, I explain why judgements competently deduced from known premisses are themselves knowledgeable. Assuming an exclusionary conception of judgeable content, I further explain how such judgements can be informative. (According to the exclusionary conception, which I develop from some remarks in Ramsey, a judgement's content is given by the hitherto live possibilities that it excludes or rules out.) I propose that the value of logic lies in its allowing us to combine different sources of knowledge, so that we can learn things that we could not learn from those sources individually. I conclude by arguing that while single-conclusion logics possess that value, multiple-conclusion logics do not.

This paper assesses the prospects of a pragmatist theory of content. I begin by criticising the theory presented in D.H. Mellor’s essay ‘Successful Semantics’. I then identify problems and lacunae in the pragmatist theory of meaning sketched in Chapter 13 of Dummett’s The Logical Basis of Metaphysics. The prospects are brighter, I contend, for a tempered pragmatism, in which the theory of content is permitted to draw upon irreducible notions of truth and falsity. I sketch the shape of such a theory and illustrate the role of its pragmatist elements by showing how they point towards a promising account of the truth conditions of indicative conditionals. A feature of the account is that it validates Modus Ponens whilst invalidating Modus Tollens.