  The central concept in the theology of On First Philosophy, however, is neither truth nor being, but oneness. Indeed al-Kindi argues for a first cause of being precisely by arguing for a first cause of oneness, and asserting that “bringing something to be” means imposing unity of a certain kind. Al-Kindi’s philosophical theology thus has two main aspects: a proof that there must be some “true One” that is the cause of the unity in all things, and a discussion of the nature of this true One. These aspects are treated, respectively, in the third and fourth sections of On First Philosophy.