The aim of this research programme is to chart the way in which ancient Stoicism, in the various phases of its existence, interacted with its cultural and intellectual context. This involves not only a study of the way in which Stoics dealt with rival systems (Platonism, Aristotelianism, Epicureanism), but also an investigation of the extent to which they were willing and able to adapt their system to contemporary Greco-Roman culture (religion, popular morality) and science (astronomy, medicine). It is to be expected that the reseach embedded in this programme, which focuses on the Sitz im Leben of Stoicism, will help us to assess the internal coherence and appeal of Stoicism as a philosophical system, and to further articulate our picture of the development of the school (for example by facing such questions as whether there really was a distinct phase of middle Stoicism). Furthermore it will contribute to our understanding of the sociology of ancient philosophical schools in general and of the practice(s) of ancient philosophical debate. The programme will be carried out by three senior scholars (Algra, Tieleman, Van Ophuijsen) working at the university of Utrecht, and by two PhD-students (it is mainly for the latter two that funding is requested from NWO). The project is complementary to a projected edition of the fragments of the early Stoics.