Cesare Cozzo

This is an introduction to Michael Dummett’s philosophy. Unlike other books on Dummett, this work considers the historical development of his philosophical thought: 1) Dummett in Oxford in the Fifties; 2) the discovery of Frege and the context principle; 3) a critique of realism in 1959; 4) theories of meaning; 5) truth-conditional, realist theories of meaning; 6) justificationist theories of meaning; 7) philosophy of time; 8) philosophy, science and religion; 9) Chronology of life and work; 10) History of the reception of Dummett’s philosophy; 11) Bibliography.

The problem I address is: how are cogent inferences possible? In § 1 I distinguish three senses in which we say that one is “compelled” by an inference: automatic, seductive-rhetorical and epistemic compulsion. Cogency is epistemic compulsion: a cogent inference compels us to accept its conclusion, if we accept its premises and we aim at truth. In §§ 2–3 I argue that cogency is intelligible if we consider an inference as a compound linguistic act in which several component acts are related to one another by a commitment that the premises support the conclusion. Non-automatic inferences are primarily public acts in an intersubjective context. But cogency arises in special contexts described in § 4, epistemic contexts, where the participants care for truth, i.e. are intellectually virtuous. An inference is cogent in an epistemic context if it stands up to all the objections raised in the context. In § 5 I consider three different kinds of cogent inferences. In § 6 I argue that in all three cases cogency is fallible and propose a fallibilist variety of inferentialism. In § 7 I distinguish context of utterance and contexts of evaluation. Cogency is relative to epistemic contexts of evaluation. However, validity, i.e. stable cogency, is transcontextual.

PART I The first chapter contains some arguments in favour of four general requirements on a theory of meaning which Michael Dummett has formulated: connection between meaning and understanding, distinction between sense and force, compositionality, and manifestability. The second chapter contains a condensed account of the theory of meaning centered on bivalent truth-conditions, and a detailed analysis of Dummett's argument against such a theory and against classical logic. The third chapter is a description of Dummett's theory of meaning centered on the notion of direct verification, and of Prawitz's semantics which can be embedded in the latter theory of meaning so as to justify intuitionistic logic. The weakest points of Dummett's idea are two: 1) it is difficult to make verificationism compatible with the holistic character of justification; 2) logical revisionism may involve a too drastic disagreement between verificationism and linguistic practice. -/- PART II. The second part contains a presentation of a theory of meaning centered on the notion which I have called immediate argumental role. The fundamental idea of the theory is that the sense of a word is given by all the argumentation rules concerning the word. Chapters IV-VII make precise the basic idea by explaining the notion of "argumentation rule" and by defining the notion of "concerning", and other notions among which "immediate argumental role of a sentence" and "global argumental role". Chapters VIII-X deal with the main philosophical features of the theory: 1) the theory satisfies the four requirements considered in the first chapter; 2) despite its compositionality, the theory is compatible with epistemological holism; 3) the theory admits the possibility of meaningful paradoxical languages; 4) the theory distinguishes between the understandability of a language and its correctness in a given epistemic situation (understandability does not imply correctness); 5) the theory is pluralist with respect to the understandability of different logics and neutral with respect to their validity.

This study presents and develops in detail (a new version of) the argumental conception of meaning. The two basic principles of the argumental conception of meaning are: i) To know (implicitly) the sense of a word is to know (implicitly) all the argumentation rules concerning that word; ii) To know the sense of a sentence is to know the syntactic structure of that sentence and to know the senses of the words occurring in it. The sense of a sentence is called immediate argumental role of that sentence. According to the argumental conception of meaning a theory of meaning for a particular language yields a systematic specification of the understanding of every sentence of the language which consists in a specification of the immediate argumental role of the sentence. The immediate argumental role is a particular aspect of the use of a sentence in arguments. But it is not the whole use in arguments, nor is the whole use in arguments reducible to the immediate argumental role. That is why, by accepting the argumental conception of meaning, we can have epistemological holism without linguistic holism. The argumental conception distinguishes between the understanding and the correctness of a language. Such a distinction makes it possible to account for our understanding of paradoxical languages. Redundancy theory of truth, realistic conceptions of truth or epistemic conceptions of truth are all compatible with an argumental conception of sense. But here it is argued that an epistemic conception of truth is preferrable. Acceptance of the argumental conception of meaning and of an epistemic conception of truth leads to a rejection of the idea of analytic truth. The argumental conception is pluralistic with respect to the understandability of different logics, and neutral with respect to their correctness.