From Discursive Practice to Logic? Remarks on Logical Expressivism


  • Rodger Kibble Department of Computing, Goldsmiths, University of London



dialogue, inference, commitments, conditionals, logical expressivism, Brandom, Bourdieu, Wittgenstein, information state, social practice theory


This paper proposes a novel account of the conditional locution as grounded in practices of goal- directed cooperative dialogue. It is argued that a conditional semantics can be obtained within a language fragment that lacks this locution, but supports assertive, inferential and directive prac- tices. We take Brandom’s logical expressivist programme as a point of departure, but argue that this programme is empirically flawed as it underestimates the pervasive context-dependence of linguistic items including logical vocabulary. We further take issue with his claim that a discursive practice involving only assertion and inference is sufficient for the conservative introduction and deployment of conditional vocabulary. A more promising route is provided by the introduction of directives, as in so-called “pseudo-imperatives” such as Get individuals to invest their time and the funding will follow: this has a conditional sense that if individuals invest their time, then funding will follow. We propose a semantic analysis for these forms which builds on Kukla and Lance’s account of prescriptives, and argue that our analysis more faithfully captures the “irrealis” nature of conditionals. The analysis is presented in terms of an information-state based dialogue model, with the information state comprising a partitioned commitment store. It is argued that our “dialogical” analysis of conditional reasoning is faithful to Brandom’s Sellarsian intuition of linguistic practice as a game of giving and asking for reasons. We conclude by contextualising and situating Brandom’s programme against the larger field of practice theory, by means of a comparison with the works of sociologist, anthropologist and philosopher Pierre Bourdieu, and suggest that this com- parison reveals further challenges to the expressivist programme. We also take note of Narasimhan et al’s recent proposals for agent-based modelling of social practice theory as a possible basis for future development.