Michael Ruse on The Cosmological Argument

In Taking God Seriously, agnostic philosopher Michael Ruse objects (rather lightly) to the cosmological argument by noting that denying the existence of God does not imply a contradiction — hence God cannot be logically necessary.

However, Ruse quickly admits that: “The great philosophers, especially Aquinas, knew this. Hence, for them, there had to be something about God that did make his existence necessary. It might not be logical necessity, but it had to be necessary nonetheless. The term used is 'aseity,’ and the claim is that God’s very essence implies his existence. The $64,000 question is just how God’s essence implies his existence.” (pg. 63 - 64)

Ruse is following Hume on the first point, who argued there is no being whose non-existence implies a contradiction. For the most part theists have agreed with this. However, Joshua Rasmussen makes several moves here to show atheism (= the denial of God’s existence) may indeed imply a contradiction. So, even if the theist happened to agree with Ruse about God’s (or anything else’s) status as a logically necessary being, that issue remains an open debate, to say the least. Either way, the point is irrelevant for cosmological arguments of the sort Aquinas advances, which trace back to that in which there is no distinction between essence and existence and how that entails its metaphysically necessary existence.

Short post on logical vs metaphysical modality here.

For Aquinas, God’s nature and existence are deduced from the fact that there must be some being in which essence and existence are not really distinct, which (with further argumentation) allows us to affirm that being as both purely actual and eternal. This puts God, qua pure actuality, beyond all categories requiring a cause: thus, whatever else God is, God is intrinsically “un-causeable.” Said differently, God could not be created nor destroyed because God has no potency for non-existence as a purely actual being, and because God is eternal God could have no beginning, no end. Hence whatever is purely actual and eternal is that which exists of metaphysical necessity — it simply cannot fail to be.

The point is that when it comes to traditional metaphysics, what is argued for initially is not a logically necessary being but a metaphysically non-composite being, and once conceptual analysis is run upon a metaphysically non-composite being we discover it is the sort of thing that cannot not exist. It is at that point we get an answer to Ruse’s question of how God’s essence implies existence: simply because God’s essence just is existence (unbounded). In other words, once we “do the metaphysics” we see Ruse is asking something silly: namely, how does God’s essence imply God’s essence (which we argued is existence!!), and the answer is because there is no distance or difference between the two. God is ipsum esse subsistens = “to be to be.”

In short, what the cosmological argument shows is that in positing everything is contingent (= only things with a real distinction between their essence and existence, exist), then nothing would exist; that is, a particular metaphysical hypothesis generates, not a logical contradiction, but a contradiction of fact. This forces us to affirm the contradictory hypothesis (= there is at least one being whose essence just is existence).

Details of that argument here.