Ian Rumfitt

The paper addresses itself to the "Homeric struggle" in the theory of meaning between those (e.g., Grice) who try to analyze declarative meaning in terms of an intention to induce a belief and those (e.g., Davidson) for who declarative meaning consists in truth conditions. (The point of departure is Strawson's celebrated discussion of this issue, in his Inaugural Lecture.) I argue that neither style of analysis is satisfactory, and develop a "hybrid" that may be-although what I take from the Gricean side in the struggle is not the notion of an intention, but that of somebody's reason for speaking as he does. The paper applies the hybrid analysis to resolve certain problems connected with the rationale for compositional, truth-theoretic semantics

Many prominent writers on the philosophy of logic, including Michael Dummett, Dag Prawitz, Neil Tennant, have held that the introduction and elimination rules of a logical connective must be ‘in harmony ’ if the connective is to possess a sense. This Harmony Thesis has been used to justify the choice of logic: in particular, supposed violations of it by the classical rules for negation have been the basis for arguments for switching from classical to intuitionistic logic. The Thesis has also had an influence on the philosophy of language: some prominent writers in that area, notably Dummett and Robert Brandom, have taken it to be a special case of a more general requirement that the grounds for asserting a statement must cohere with its consequences. This essay considers various ways of making the Harmony Thesis precise and scrutinizes the most influential arguments for it. The verdict is negative: all the extant arguments for the Thesis are weak, and no version of it is remotely plausible.

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.