Muslims, like Jews and Christians, recognize no other divinities but the all-powerful Creator of the universe. They adhere to the fundamental belief in God’s oneness, or tawḥīd. The philosophical treatises that came into Arabic-speaking culture also typically recognized a single first cause of all things. The falāsifa used Hellenic sources to argue for, and explicate, the doctrine of tawḥīd, taking them as a jumping-off point for their own original ideas. ‘God and being’ outlines the ideas of al-Kindī, who portrayed God as ‘the True One’ free of all multiplicity; Avicenna’s influential proof of God’s existence; Suhrawardī whose metaphysics describes God as the ‘Light of lights’; and sufi conceptions of God as the true reality underlying all things.