Qualifying and quantifying medical uncertainty in 10th-century Baghdad: Abu Bakr al-Razi.

Al-Razi rose to become a hospital director both in Rayy (his home town, and now a suburb of Tehran) and Baghdad. This hospital environment proved important for his medical research. By the 10th century, hospitals in Baghdad had developed into quite sophisticated institutions. For instance, in the 920s and 930s, a powerful vizier by the name ‘Ali ibn ‘Isa endeavoured to improve public health, both by maintaining hospitals and sending doctors to areas where there was inadequate medical provision. The hospitals were Islamic charitable foundations with sometimes substantial endowments, so they benefitted from both legal and financial security; but ‘Ali ibn ‘Isa specified that they should serve nonMuslims as well as Muslims. Moreover, the medicine practised in these hospitals was not based on religious beliefs, but on the humoral pathology inherited from the Greeks, as the writings of the hospital physician al-Kaskari demonstrate. In this sense, the Islamic hospitals offered – somewhat paradoxically – a non-religious and nonsectarian service: physicians and other practitioners from various backgrounds catered for equally diverse patients in a non-confessional medical system. The development of the hospitals meant that elite medicine moved to them, and some of the most highly regarded doctors looking after patients in the upper echelons of society worked and taught in them. In addition, given their large numbers of patients, hospitals provided an infrastructure for research.