Erotetic logic, uncertainty and therapy: Galen and alexander on logic and medicine

Syllogistic is grounded upon dialectics. Dialectics is a version of erotetic logic, because it deals with questions and answers. This paper intends to explore the erotetic logics of Galen and of Alexander of Aphrodisias in order to establish whether the differences in their logical systems correspond to differences in their understanding of medicine. Galen and Alexander of Aphrodisias were almost contemporaries. Both of them shared the idea that doctors should know logic to practice medicine. The radical difference between Alexander and Galen consists in the fact that Alexander has a modal logic, whereas Galen does not. In other words, the premises-the answers in a dialogical exchange-include a modal operator for Alexander, but not for Galen. This absence is not without consequences. This will become clearer if one pays attention to the role of contingency syllogistic within Alexander's own account of medicine.