Introduction

This chapter discusses in general terms Charles S. Peirce's claim that "logic is best considered as semiotics". The general semiotics that Peirce has imagined is rather a department of logic, and a department that is still subservient to the objectives of logic itself. Unlike Saussure's linguistics, logic is not placed by the late Peirce within the larger horizon of a general science of signs. The chapter deals with the declared source of the name of the first department of logic, namely the treatise De modis significandi, sive grammatica speculativa of Thomas of Erfurt, which at the end of the nineteenth century was still attributed to John Duns Scotus. It briefly focuses on the affinities and differences between Peirce's grammatical enterprise and its distinguished medieval antecedent. Finally, the chapter contains some brief remarks on the methodological principles that have guided the author in the reconstruction and in the exposition of Peirce's speculative grammar.