Abstract

One of the classical arguments for the existence of God is the ontological argument. In the second half of the twentieth century, this argument was updated, and triggered new philosophical discussions under the title of “modal ontological argument.” These discussions have expanded with the emergence of the modal versions of the cosmological argument. However, despite the intense interest in arguments for the existence of God, the contemporary scholarship in the philosophy of religion largely overlooks the problem as to whether God is unique or not. In this paper, I aim to update Taftazānī’s argument for the uniqueness of God by means of the conceptual tools of the possible world semantics. Taftazānī’s argument is known as burhān al-tamānu in the Islamic kalām, and aims to show that postulating two omnipotent gods will result in contradictions due to a possible conflict between the two divine wills. The term tamānu refers to the conflict between these wills. So, I argue that this argument, supplemented by the conclusion of the modal ontological or cosmological argument, shows that there is only one God. I call this extended argument “A Modal Argument for the Uniqueness of God.”