Back in March I authored a post titled “Omnipotence and Monotheism,” in which I argued that the divine property of omnipotence does not prove monotheism as I had once thought because power is not a substance, and thus need not be exhausted by a single being.  Power is simply the ability to do some X.  Omnipotence, then, is just the property of possessing the ability to do any and all things that are logically possible to do.  It seemed logically possible to me that there could be more than one being who possessed the ability to do anything that is logically possible.  The only logical grounds I could see for postulating monotheism was the principle of parsimony: no more than one God is needed to explain phenomena such as the origin of the universe, and thus there is no reason to postulate more than one divine being.  Parsimony, however, does not make monotheism logically necessary.

With further dialogue on this topic in another forum, I believe I now have the logical grounds on which to conclude that monotheism is logically necessary, and ironically, it involves the divine property of omnipotence!  Any being – if he possesses the property of omnipotence – must possess the ability to destroy other beings, and yet two omnipotent beings could not destroy each other.  If omnipotent being A (OBA) cannot destroy omnipotent being B (OBB), then OBA lacks the power to do some X, and thus is not omnipotent after all.  The same would be true of OBB, leaving us without a being that is truly omnipotent.  And yet, if God is a metaphysically necessary being and omnipotence is a divine property, then omnipotence is a metaphysically necessary property.  Since the property of omnipotence can only obtain in a world in which a single being possesses such a property, there can only be one divine being.  While omnipotence does not prove monotheism in the manner I originally envisioned, omnipotence does make monotheism logically necessary.

As an interesting aside, I thought this argument would also provide a good argument against a Trinitarian view of God, and for a Unitarian view.  I reasoned that if omnipotence requires the ability to destroy other beings, then the Father must be able to destroy the Son and Spirit (and the other two persons must be able to do likewise).  If such was possible, then two of the persons in the Trinity must lack the divine property of omnipotence, and thus cannot be God.  A participant in the forum, however, pointed out that since all persons of the Trinity share the same being, the Father could not destroy the Son or the Spirit without destroying His own being.  Seeing that it is logically impossible for a metaphysically necessary being to destroy His own being, it would be logically impossible for the Father to destroy the Son/Spirit, the Son to destroy the Father/Spirit, or the Spirit to destroy the Father/Son.  Omnipotence does not entail the ability to do the logically impossible, and thus the inability of the persons of the Trinity to destroy one another does not count against their deity, nor the logical possibility of a divine Trinity.