""Both Christianity and Islam are logocentric," he told his students, "meaning they are focused on the Word. In Christian tradition, the Word became flesh in the book of John: 'And the Word was made flesh, and He dwelt among us. 'Therefore, it was acceptable to depict the Word as having a human form. In Islamic tradition, however, the Word did not become flesh, and therefore the Word needs to remain in the form of a word … in most cases, calligraphic renderings of the names of the holy figures of Islam.""

Source: Inferno.