Medieval Islamic philosophy was steeped in both Aristotelianism and Neoplatonism from its ninth-century beginnings with al-Kindi, but the influence of Neoplatonism becomes more clearly visible in the tenth and eleventh centuries with Al-Farabi and Avicenna. Al-Farabi expanded on Plato's concept of an ideal city ruled by philosopher-kings to develop a political philosophy that could accommodate the religious and cultural diversity central to Islamic nations. On the other hand, both al-Ghazali and Ibn Rushd vigorously opposed Neoplatonic views.