Online research in philosophy

What is the relationship between logic and reasoning? How do logical norms guide inferential performance? This paper agrees with Gilbert Harman and most of the psychologists that logic is not directly relevant to reasoning. It argues, however, that the mental model theory of logical reasoning allows us to harmonise the basic principles of deductive reasoning and inferential perfomances, and that there is a strong connexion between our inferential norms and actual reasoning, along the lines of Peacocke’s conception of inferential role.

The entire development of modern logic is characterized by various forms of confrontation of what has come to be called proof theory with what has earned the label of model theory . For a long time the widely accepted view was that while model theory captures directly what logical formalisms are about , proof theory is merely our technical means of getting some incomplete grip on this; but in recent decades the situation has altered. Not only did proof theory expand into new realms, generalizing the concept of proof in various directions; many philosophers also realized that meaning may be seen as primarily consisting in certain rules rather than in language-world links. However, the possibility of construing meaning as an inferential role is often seen as essentially compromised by the limits of proof-theoretical means. The aim of this paper is to sort out the cluster of problems besetting logical inferentialism by disentangling and clarifying one of them, namely determining the power of various inferential frameworks as measured by that of explicitly semantic ones.

According to Conceptual Role Semantics ("CRS"), the meaning of a representation is the role of that representation in the cognitive life of the agent, e.g. in perception, thought and decision-making. It is an extension of the well known "use" theory of meaning, according to which the meaning of a word is its use in communication and more generally, in social interaction. CRS supplements external use by including the role of a symbol inside a computer or a brain. The uses appealed to are not just actual, but also counterfactual: not only what effects a thought does have, but what effects it would have had if stimuli or other states had differed. The view has arisen separately in philosophy (where it is sometimes called "inferential," or "functional" role semantics) and in cognitive science (where it is sometimes called "procedural semantics"). The source of the view is Wittgenstein (1953) and Sellars, but the source in contemporary philosophy is a series of papers by Harman (see his 1987) and Field (1977). Other proponents in philosophy have included Block, Horwich, Loar, McGinn and Peacocke (1992). In cognitive science, they include Woods (1981) and Miller and Johnson-Laird (1976). (See references in Block, 1987.).

According to Conceptual Role Semantics ("CRS"), the meaning of a representation is the role of that representation in the cognitive life of the agent, e.g. in perception, thought and decision-making. It is an extension of the well known "use" theory of meaning, according to which the meaning of a word is its use in communication and more generally, in social interaction. CRS supplements external use by including the role of a symbol inside a computer or a brain. The uses appealed to are not just actual, but also counterfactual: not only what effects a thought does have, but what effects it would have had if stimuli or other states had differed. The view has arisen separately in philosophy (where it is sometimes called "inferential," or "functional" role semantics) and in cognitive science (where it is sometimes called "procedural semantics"). The source of the view is Wittgenstein (1953) and Sellars, but the source in contemporary philosophy is a series of papers by Harman (see his 1987) and Field (1977). Other proponents in philosophy have included Block, Horwich, Loar, McGinn and Peacocke (1992). In cognitive science, they include Woods (1981) and Miller and Johnson-Laird (1976). (See references in Block, 1987.).

According to inferential role semantics (IRS), for any given expression to possess a particular meaning one must be disposed to make or, alternatively, acknowledge as correct certain inferential transitions involving it. As Williamson points out, pejoratives such as ‘Boche’ seem to provide a counter-example to IRS. Many speakers are neither disposed to use such expressions nor consider it proper to do so. But it does not follow, as IRS appears to entail, that such speakers do not understand pejoratives or that they lack meaning. In this paper, I examine recent responses to this problem by Boghossian and Brandom and argue that their proposed construal of the kind of inferential rules governing a pejorative such as ‘Boche’ is to be ruled out on the grounds that it is non-conservative. I defend the appeal to conservatism in this instance against criticism and, in doing so, propose an alternative approach to pejoratives on behalf of IRS that resolves the problem Williamson poses.

In this paper we first propose an exact definition of the concept of inferential role, and then go on to examine the question whether subscribing to inferentialism necessitates throwing away existing theories of formal semantics, as we know them from logic, or whether these could be somehow accomodated within the inferentialist framework. The conclusion we reach is that it is possible to make an inferentialist sense of even those common semantic theories which are usually considered as incompatible with inferentialism, such as the standard semantics of second-order logic.

According to inferential role semantics (IRS), for an expression to have a particular meaning or express a certain concept is for subjects to be disposed to make, or to treat as proper, certain inferential transitions involving that expression.1 Such a theory of meaning is holistic, since according to it the meaning or concept any given expression possesses or expresses depends on the inferential relations it stands in to other expressions.

According to inferential role semantics (IRS), for an expression to have a particular meaning or express a certain concept is for subjects to be disposed to make, or to treat as proper, certain inferential transitions involving that expression.1 Such a theory of meaning is holistic, since according to it the meaning or concept any given expression possesses or expresses depends on the inferential relations it stands in to other expressions.