Speculative Grammar   
var.
Grammatica Speculativa, Originalian Logic

Speculative Grammar

According to Christian Kloesel (1981, p. 130), Peirce’s attribution of speculative grammar to Duns Scotus is mistaken; later research has identified the author of De modis significandi, sive grammatica speculativa as Thomas of Erfurt rather than Scotus. (See also Thomas of Erfurt in the Stanford Encyclopedia of Philosophy.)