 The Perfect City and Political Regime make particularly striking use of Fârâbî’s “general” metaphysical treatises, the Book of Letters and On the One, in their accounts of the senses in which the First is one. The Perfect City and Political Regime go through a list of attributes of God, and try to show that (and in what sense) each of them belongs to the First, and from a Muslim point of view one of God’s most important attributes is that he is one—first in the sense that there is no other god, and then also in the sense that he contains no internal multiplicity. The Perfect City marks several senses in which the First is “one”. It is one in that no other being shares its species of existence (66,5–7), and it is one in that it is “undivided” or “indivisible”, into quantitative parts or any other kind of parts (68,2–6); but then, finally,