Introduction to Charles S. Peirce’s Existential Graphs Beta System

Abstract

Existential Graphs (EG) are logical notations of a topological nature, and are always among the most original inventions of C S. Peirce (1839-1914). It is a logical-diagram graph system through which, according to Peirce, any thought development can be represented with precision (CP 4.530). They are divided into three sub-systems “alpha, beta and gamma”, approximately equivalent to the classical prepositional calculus, to the classical predicate calculus of the first order, and to a type of modal logic. We propose to present the beta system. What we will show will be confined to the monadic predicate calculus, with emphasis on the Aristotelian categorical syllogisms.