Roczniki Filozoficzne

Volume 14, Issue 1, 1966

Two Concepts of Consequence in Peter Abelard and Strict Implication in Lewis and Ackermann

In his „Topics”, forming part of his Dialectics, Abelard discusses the sense and truth-conditions of hypothetical sentences. In this aligns himself, not to the tradition of the Stoics, but, through Boethius, to the tradition of the old Peripatetics, namely to Eudemus. Among, hypothetical sentences, a basic type is the conditional sentence, or consequentia. In the present article it is shown that Abelard rejects the truth-functional interpretation and the probability-interpretation for conditional sentences (consequentia) and admits only two interpretations, of which one is modal and in complete agrees with the concept of strict implication of Lewis, and the second is inferential. This agrees with Ackermann’s concept of strict implication. Abelard is an advocate of inferential interpretation, free of paradoxes, to which a modal interpretation leads.