Why can’t I argue that God exists noncontingently and is an abstract object? Some say it is because abstract objects lack causal power, and thus to argue as such would deny God at least one essential characteristic which any interesting concept of God cannot lack—omnipotence. But why can’t abstract object possess causal power?

Interesting question. Some philosophers have attributed to abstract objects divine attributes like being eternal and timeless. Perhaps some abstract objects (like the properties of justice and beauty) might be worthy of worship. I have actually argued that abstract objects do have causal roles, so I am sympathetic with your inquiry! Their causal role (in my view) takes place in accounting for our intentionality and thinking. When you think about 1+1, the reason why you reason that 1+1=2 is that you grasp necessary relationships between numbers, which are abstract objects. Moreover, for some of us who think God exists non contingently, we suppose that there is the abstract state of affairs of there being a non contingent, necessarily existing God. And no less a philosopher than Plato suggests that the Good might be the source of what is.

However while abstract objects might have some causal powers, few have thought they can have intentional powers (e.g. the property of justice as an abstract object cannot itself act justly or be loving or know things or hear prayers or care about the world....) This limitation would mean that one or more abstract objects would not be able to function / act as God is thought to do so in most theistic traditions.

Be that as it may, a contemporary, brilliant philosopher, Victoria Harrison, has recently argued for comparing God to an abstract object (she did so last summer at a philosophy conference in Brazil). You might do a search for her work on this topic.

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