When Christian physicians were driven out of Constantinople they carried their knowledge of ancient Greek medicine and science to the Arabs. Mohammed recommended that the insane be confined and treated. In the Koran the insane are considered irresponsible. Only the ignorant and superstitious considered them as possessed. In Egypt idiots and imbeciles were considered as beings whose spirits were in heaven while their material bodies remained among the mortals. While the first hospitals which included insane among their patients were probably in Constantinople, the first Arabian hospital for insane was established in Bagdad in 765. They later spread by way of Egypt through Northern Africa to Spain. The first European asylum was founded in Valencia by the Moslems in 1409. In the ninth century Ishaq-Ibn-Imran wrote a treatise on melancholiThe Arabs not only preserved the knowledge of ancient Greece, but developed and transmitted it centuries later to the Europeans.