This book places in dialectical interaction the strictly philosophical thought and the theological one, to investigate not only what but also how was the thought in "medieval" Islam. Certainly, the concept of the uniqueness of God remains, but the book, comparing the theological aspects of philosophy and the philosophical ones of theology, try to highlight the interaction between the rational sciences (‘ulum’ aqliyya) and the traditional sciences (‘ulum naqliyya) in classical Islam. The texts of Massimo Campanini, expert scholar of the thought in the islamic world, are landmarks in the academic world and this new volume revolutionizes the normal approaches to arab philosophy and theology.