When the Inference ‘p is true, therefore p’ Fails: John Buridan on the Evaluation of Propositions

Abstract

For John Buridan, truth-bearers are assertions. This fact explains why the inference ‘p is true, therefore p’ may fail. On the one hand, the tense of the verb plus the time of utterance do not determine the time about which a sentence is intended to be true: the intention of the speaker is needed. On the other hand, since the meaning of vocal and written words is conventional, it may seem that they can be used with different meanings on each side of the inference. While the antecedent may talk about a situation different from the present one, this doesn’t make it the actual situation of utterance, and the words have meanings only in the actual situation of use. Although such situations are different, in both of them we are asked to see the importance of identifying features of which the disquotational schema doesn’t keep track and that can only be specified in the context of use.