Middle Voice - an intriguing lack in Stoic terminology

The Stoics recognized four types of predicate, orthá, hýptia, oudétera, currently translated as ‘active’, ‘passive’, and ‘intransitive’ verbs, and antipeponthóta, a subtype of hýptia which is identified with reflexive or reciprocal verbs. The terms orthá and hýptia have been derived from the lexicon of gymnastics. The designation antipeponthóta, instead, has been borrowed from geometrical terminology. The concepts of “voice” and “transitivity” lie under the Stoic recognition of the types of predicate, but the lack of the term diathesis in their taxonomy is intriguing. This absence should be a proof of a later debate about the verbal category of “voice”, which remained unresolved in the Grammarians’works. Our aim is to investigate the relevant aspects in the Stoic taxonomy. For example, the argument “construction”, syntaxis in Greek, seems to be the most important feature in order to classify ‘right’, ‘supine’ and ‘neuter’ predicates, whereas the semantic factor is essential to discern the group of antipeponthóta, literally ‘be affected in turn’. In spite of the lack of terms such as ‘diathesis’ and ‘middle voice’, the Stoic reflection on the predicate is very important (for us) to understand one of the most controversial categories of Linguistics