The criticism of modist grammar is based on a fundamental redefinition of the concept of sign, coming about after the mid-13th century. For the translocation of signification in the proper sense from the word to the intellect is based on the presupposition that, whatever Augustine may have said, mental concepts are signs themselves. [...] Once again, it is the mid-13th century where a conceptual change is taking place which, although at first it may seem to be a matter of nuance, turns out to be one of the most important junctures in the history of semiotics: mental concepts — without at first losing their status of being likenesses of things — begin to be characterized as signs of things (signa rerum).