Genesis and Substance in Posidonius’ Stoicism

The Posidonian fragment regarding the process of genesis as described by Arius Dydimus (Epitomefr.27 Diels) turns up twice in Stobaeus’ Eclogae. The passage occurs in a section (I. 20) entitled On Generation and Destructionwhich is mostly concerned with whether the cosmos is destructible. It is followed by a reference to criticism of Mnesarchus, the pupil of Panaeitus. The fragment recurs in Stobaeus at the end of I. 17; this is the chapter which contains Chrysippus’ orthodox classification of mixtures as juxtaposition, fusion and blending (παραθέσει,συγχύσει,κρᾶσιν). As we shall see, there is substantial evidence that Posidonius revised the Stoic position and proposed a new concept of genesis.