Paradoxical versus modulated conditional inferences: An explanation from the Stoicism

Abstract

According to standard propositional logic, the inferences in which the conditional introduction rule is used are absolutely correct. However, people do not always accept inferences of that kind. Orenes and Johnson-Laird carried out interesting experiments in this way and, based on the general framework of the mental models theory, explained clearly in which cases and under which circumstances such inferences are accepted and rejected. The goals of this paper are both to better understand some aspects of Stoic logic and to check whether or not that very logic can also offer an account on this issue. My conclusions are that, indeed, this later logic can do that, and that the results obtained by Orenes and Johnson-Laird can be explained based on the information that the sources provide on Stoic logic.

The ten kinds of conditionals and Chrysippus’ criterion

“…On the one hand, it is further support for the theory of mental models: it gives one more characteristic to the list of interpretations of the conditional, which appears to make that list even more plausible. On the other hand, in a way consistent with the literature (e.g., López-Astorga, 2016), it shows that to keep addressing theories from the past in general and the one of Chrysippus of Soli in particular is relevant. So, following that very literature, it seems appropriate to continue to use criteria such as the one Chrysippus presented for the conditional in studies akin to that described in the present paper.…”

“…It is not the first time Chrysippus' criterion is related to the theory of mental models (e.g., López-Astorga, 2016). Nevertheless, the idea now is not to detect commonalities between Stoic logic (represented by Chrysippus) and the aforementioned theory.…”

“…Chrysippus' criterion is relevant. It has been used to explain even contemporary cognitive issues (e.g., López-Astorga, 2016). For this reason, this paper will resort to it too.…”