  Al-Kindi’s account of astral causation and providence is a very good example of his philosophical method: combining and building on ideas taken from Aristotle, later Greek philosophers, and “scientific” authors like Ptolemy, he gives a rational account of a central concept in Islam. Prostration shows that he is even willing to use such an account to expound the Koran itself. Al-Kindi is confident that, once exposed to judicious presentations of Greek wisdom, his more enlightened contemporaries and sponsors will agree that these foreign texts can be used — jointly with autochthonous “Arabic” disciplines like grammar — in the service of a deeper understanding of Islam itself.