History of Philosophy
The Stoics on validity: conflict, relevance and dialectic
The Stoics distinguished three different notions of validity. Firstly, all valid arguments are generically valid. Of these arguments, many are syllogistically valid as well; the ones that are not, are called valid “in the specific sense”. Since scholars working on Stoic logic have focussed their research on Stoic syllogistic, the Stoic notion of syllogistic validity has received the most attention. In this article I will instead discuss their concept of generic validity. In the sources on the Stoics we find two different principles governing generic validity: the conflict principle and the conditionalization principle. The conflict principle states that an argument is valid if the opposite of its conclusion conflicts with the conjunction of its premisses.
The conditionalization principle states that an argument is valid if one can form a true conditional with the conjunction of the premisses as the antecedent and the conclusion as the consequent.
I will argue that it is the conflict principle that is central to generic validity. I have two arguments for this position: (1) the conditionalization principle turns out to revolve around conflict as well, and (2) several additional requirements for validity which are encountered in the sources can be derived from the conflict principle. I will argue for each of these claims in turn. In doing so, I will show both that conflict requires a relation of relevance and that it has dialectical roots.
|Last modified:||19 September 2014 3.38 p.m.|