Abstract

In his logical treatises, John Mair develops a method and a set of rules for the verification of modal propositions, which is in the spirit of his predecessors Ockham and Buridan, but ultimately goes beyond them. He calls this method positio de inesse. It is also by this method that the truth conditions for divided modal propositions are set out. There is a standard interpretation of it as a form of reductionist method, and scholars have been tempted to think that it was motivated by an implicit rejection of de re modal properties shared by Mair and other sixteenth- century nominalists. After presenting the background to Mair’s writings on the semantics of modal propositions, in this paper we revisit Mair's version of the method of positio de inesse. We argue that it is based on some basic semantic rules and contend that this procedure analyzes divided modal propositions into singular de re sentences referring to possible objects. Consequently, we conclude that this method does not reflect a reductionist approach to modal discourse. We instead provide an alternative interpretation.