Plantinga and Ash‘arites on Divine Simplicity
Authors: MUHTAROĞLU Nazif 
Published: December 2020

The doctrine of divine simplicity has been upheld across various religious traditions, including Christianity and Islam. The mainstream interpretation of divine simplicity identifies God with His attributes. I examine and discuss certain criticisms of this doctrine. I consider Alvin Plantinga’s arguments from the recent Western literature, and certain arguments given by ‘Abd al-Qāhir Baghdādī and Sa‘d al-Dīn al-Taftāzānī from the Ash‘arite tradition. After reconstructing these arguments, I discuss two main objections that can be directed to them. Plantinga’s criticism aims to indicate some unacceptable consequences of divine simplicity. First, if divine simplicity is accepted, then all the divine attributes would be identical with divine essence, and thus divine attributes would be identical to each other. That is to say, there would be only one attribute if they are all identical. However, this result is not easy to accept given the multiplicity of divine attributes such as omnipotence, omniscience, and omnibenevolence. Second, via similar reasoning, it can be shown that God is not a personal being who created the universe but an abstract object since properties are abstract objects. These absurd consequences follow from divine simplicity. If they are not to be accepted, divine simplicity must be rejected. These arguments exemplify the form of reductio ad absurdum, and the same form of arguing against divine simplicity is also found within the Ash‘arite tradition. On the one hand, ‘Abd al-Qāhir Baghdādī argues that divine attributes would be identical if divine simplicity is accepted. The identity of divine attributes implies that their scopes are identical as well. However, the scope of divine power and divine knowledge cannot be identical since God knows Himself, but His power does not apply to Himself. Sa‘d al-Dīn al-Taftāzānī, on the other hand, holds that attributes are not independent beings but can exist only as dependent upon something else. If divine attributes are assumed to be identical with divine essence, then divine essence would be a dependent being as attributes are. As we have seen, these arguments also purport to show some absurdities following from the doctrine of divine simplicity and deny this doctrine on the basis of those absurdities. Thus, they exemplify the form of reductio ad absurdum as Plantinga’s arguments. The first objection that could be directed against the above arguments aims to show that we cannot make any distinction in God since God is absolutely distinct from any other being. Thus, we cannot even differentiate between divine attributes and God’s essence. If this is the case, all the arguments considered rely on a mistaken presumption about some kind of distinction between God and divine attributes. I argue that this position is inconsistent with the doctrine of divine simplicity. Divine simplicity is a theoretical position that identifies divine attributes with God. To be able to make that identification, the doctrine already presumes some kind of distinction between God and divine attributes. The second objection does not deny that there is some kind of distinction. It aims to explain it in terms of the distinction between sense and reference as proposed by Frege and analogical predication as introduced by Aquinas. I argue that this attempt is futile and amounts to the first objection.