Galen was proud of his not being enslaved to any philosophical sect. He used to set his intellectual freedom against the sectarian spirit widespread among the intellectuals of his time. However, on many occasions he declared his preference for Plato’s philosophy. This article discusses the limits and the meaning of Galen’s Platonism. He strongly shares the theory of the tripartition of the soul as set out in the Republic, on which he bases the doctrines discussed in De placitis Hippocratis and Platonis. On the other side, Galen rejects as extraneous to the field of scientific demonstration the main elements in Plato’s philosophy, such as metaphysics, theology, cosmology, and immortality of the soul, all of which belong to the dimension of pithanon, more rhetorical than epistemic. The theory of ideas is not even mentioned. From this point of view, Galen can certainly not be considered a follower of Middle Platonism. More complex is the question of demiurgical providence and the teleological organization of nature. Here Galen is undoubtedly influenced by Plato’s Timaeus, but careful examination shows that he is closer to the immanentism of Aristotelian and even Stoic teleology.
Keywords: Galen, Greek medicine, Platonism, epistemological probabilism