Abstract
Alexander of Aphrodisias and Bardaisan, at the end of the second/beginning of the third century CE, are part of a cultural context where astrology, beyond popular or civic beliefs, is integrated into a cosmological reflection on the principles of reality. In such a context, they analyse the concepts of nature and free choice with the project of limiting the influence of fate, in the face of adversaries who submit everything to destiny. In both cases, the aim is not to deny but to recognise the causal power of fate, while nonetheless assigning it to a particular sphere of reality rather than the whole. In both cases, too, it is mainly through the relations between nature, fate and free choice that this restrictive assignment takes place. Here we will study, regarding a few points, the different strategies by which these two authors fit into the ancient anti-fatalist tradition and contribute to the emergence of the idea of free will in late antiquity.