 Here Fârâbî is taking a stand on an issue that was controversial among Aristotelians, by saying that we do not come to know God through the science of physics, even though Aristotle argues in his Physics 8 that the eternal circular motions are caused by eternally unmoved movers. Fârâbî is saying that the right way to come to know God is as a cause of existence rather than as a cause of motion. On the face of it, this could be taken in two ways. (a) Perhaps Fârâbî means that God is both a cause of existence (to everything) and a cause of motion (to the things that move, i.e., to bodies rather than to incorporeal substances), but that the right way to gain scientific knowledge of God is to know him as the cause of existence. Fârâbî’s reason might be that, when we know about God that he is a first cause of motion (an unmoved mover), we do not thereby know what God is, since what God is must apply only to God, and there are many unmoved movers, of the many circular motions in the heavens. Fârâbî’s point may be that there is only one first cause of existence (although many first causes of motion), and knowing about God that he is a first cause of existence gives us knowledge of what God is. (b) In fact, however, Fârâbî thinks that the first cause of existence is prior to the first cause of motion in a stronger sense: knowing the first cause of motion does not give us knowledge of God, because God is not a cause of motion at all. On Fârâbî’s account in the Perfect City and Political Regime, God is not the first of the unmoved movers, but is rather a cause of existence to the unmoved movers and thus indirectly to everything else. So an ascent to the first cause of motion does not get us to God at all, but only to some lower being: only a study of the causes of being will get us to God.