Ancient Quantifier Logic (2209.03388v9)

Abstract: In this paper we argue and present evidence for the use of the natural deduction rules for universal and existential quantifiers in ancient philosophy. More specifically, we present evidence for the use and understanding of such rules for multiple quantification over non-necessarily monadic predicates and nested quantifiers over non-necessarily monadic predicates - all which amounts to the possession of mechanisms for dealing with multiple generality. This work aims to complement the paper by Bobzien and Shogry\cite{mult} which argues that Stoic logicians had already all the elements necessary to deal with multiple generality. While we also draw some evidence from Sextus Empiricus (a common source for Stoic logic) our focus is not on the Stoics but on logical aspects of Aristotle, Euclid, Galen and Proclus. Bobzien and Shogry argued for the ability of Stoic logic to express multiple generality through regimentation and anaphora - universal quantification is expressed by the tis + ekeinos construction on conditionals - but say relatively little about deduction rules. Our focus is on the quantifier rules themselves, specifically from the point of view of natural deduction with some incursions into dependent-type theory. This paper shares with Bobzien and Shogry the general aim of arguing for a 'somehwhat more gradual development' of the the logic of multiple generality from Aristotle to Frege.