Abstract

_Abstract_ The mental models theory claims that human thought is mainly semantic and consists of analyses of the possibilities that the sentences refer to. The theory has a great empirical support. However, it can be thought that, if it actually shows how the human mind works, it should be possible to find ancient texts authored by philosophers or logicians whose arguments reveal identifications and comparison of semantic possibilities. In this paper, I try to argue that, indeed, texts of that kind are to be found in the ancient sources. In particular, I comment on a fragment written by Aulus Gellius in which an analysis of possibilities is clear. _Keywords:_ ancient philosophy, mental models, possibilities, reasoning, semantics.