In search of the intuitive notion of logical consequence Catarina Dutilh Novaes

After decades of predominant focus on the notion of logical truth, the debate on the
concept of logical consequence among philosophers and logicians was re-ignited by J.
Etchemendy’s book The Concept of Logical Consequence (1990). His main tenet was
that the model-theoretic notion of logical consequence did not capture adequately the
corresponding intuitive notion. One of Etchemendy’s central claims was that the intuitive
notion could be understood essentially from two different perspectives, one
representational and one interpretational – and that the model-theoretic notion failed to
match either.
Some years ago, S. Shapiro (1998) sought to vindicate the model-theoretic notion of
logical consequence; one of his arguments was that the dichotomy
representational/interpretational notion of logical consequence was in a certain way
infelicitous, since, according to him, a faithful rendering of the intuitive concept would
have to have elements of both notions. Clearly, the resolution of issue as to whether the
model-theoretic notion correctly captures the intuitive notion presupposes an at least
minimally adequate characterization of this intuitive notion. Shapiro claimed that
Etchemendy hadn’t really provided such a characterization1, and attempted to formulate
one himself. He further claimed that, thus characterized, the intuitive notion was indeed
correctly captured by the model-theoretic notion (albeit with some adjustements).2
In this paper, I do not discuss Shapiro’s defense of the model-theoretic notion; rather I
examine his contention that the best rendering of the intuitive notion of logical
consequence is what he called the ‘conglomeration’ notion, that is, the hybrid notion that
combines both the representational and the interpretational view on consequence. More
specifically, I claim that such a hybrid view was held by the medieval logician John
Buridan (Cf. Hubien 1976 – henceforth TC), and that this fact offers significant historical
support to Shapiro’s version of the intuitive concept of (logical) consequence.