Abstract

Conference paper presented at the 10th International Congress of Logic, Methodology, and Philosophy of Science, Florence, Italy (19-25 August 1995). Extrapolation here refers to the act of inferring more widely from a limited range of known facts. This notion of extrapolation, especially when applied to past events, has recently been used to formulate a pragmatic definition of truth. This paper shows that this definition has serious problems. The pragmatic definition of truth has been formulated in discussions on internal realism. In this paper, the basic internal realist starting point, as expounded in the works of H. Putnam and N. Jardine, will be taken to be the claim that the distinction between judgements that are true from judgements that are false is explainable from within our judgement-forming faculty — no recourse to the external world is necessary. The paper first shows how the pragmatic definition of truth involves a counterfactual statement. It then describes how the counterfactual definition is apparently justified by an inductive argument. In the final step, this justification is shown to be unsuccessful.