Published online by Cambridge University Press: 15 February 2018
Medieval Islamic philosophy and medieval Jewish philosophy are, for the most part, Platonic in character. We do not mean by this that these medieval philosophers adhere slavishly to one or another metaphysical dogma widely attributed to Plato. Rather, we mean that, for the most part, they follow a Platonic approach to the relation between theoretical and practical science—that is, they tend to avoid drawing this distinction or to blur the distinction. In contrast, medieval Christian philosophy, especially medieval Christian political thought, not only embraces but even deepens the divide that Aristotle established between theoretical and practical science. Due in no small part to this divide, Christian thinkers such as Aquinas (1225–74 CE), Dante (1265– 1321), and Marsilius of Padua (1275–1342) find in Aristotle an important resource for thinking about secular political powers (practice), at least to some extent, in isolation from the ecclesiastical power (theory). After all, if theoretical science can be separated from practical science, then why not separate ecclesiastical power from secular political power? By rejecting Aristotle's theoretical- practical divide, at certain crucial junctures, medieval Islamic and Jewish philosophers make such a separation of politics from religion a more remote possibility. Medieval Muslims and Jews felt little need or desire to separate secular from ecclesiastical powers. Leaving aside the practical issue of the relation between these two powers, the key reason for the avoidance of the theoreticalpractical distinction in Muslim and Jewish philosophical circles—especially in Islamic and Jewish political philosophy, where one might expect it to be most in play—is that Muslim and Jewish Law are both comprehensive or total Laws, covering both actions and beliefs, the practical and the theoretical.
The suppression of this divide between theoretical and practical science has far-reaching consequences for the teaching and study of medieval Islamic and Jewish philosophy. First, one cannot assume in this setting as something of a default view, as one often might in the Christian setting, that theology provides the (theoretical) ground for (practical) human affairs. In this respect, medieval Christian thinkers tend to follow a model derived from the Bible. From certain claims about God, certain claims about the political (used broadly to cover ethics as well) order can be inferred.