God implies that God necessarily exists if he possibly exists. Conclusion: so God
necessarily exists.
If premise 3 of thefirst Cartesian argument was our sole target, then premise 3
of the second Cartesian argument will probably also be our sole target. But premise
3 is plausible, perhaps more plausiblethan premise 3, unless we countenance
essences of impossible objects. This suggests that the common premises 1 or 2 are
likely targets.
In light of these remarks, one might wonder about the relevance of God’s identity
with His essence for the success of the ontological argument. In my terminology, the
fact that an object is identical with its ultimate ontic essence is not sufficient for the
success of an ontological proof of the existence of that object. In fact, the question of
whether an object is identical with its ultimate ontic essence turns out to be pretty
much irrelevant.^87 What matters isn’t the ontic ground of the total propositional
essence of an object, but instead is whether (i) that propositional essence includes
the proposition that the object exists (in some specific way or just in general), and
(ii) propositional essences are necessarily true. So, for example, Descartes might
be his own ultimate ontic essence, but since the total propositional essence of
Descartes consists merely in that he is thinking but does not include that he exists,
no ontological proof of the actual existence of Descartes will succeed.^88
A second observation of the ontological argument is that the versions presented
here do not require that existence in any sense be a property.^89 Both versions merely
require that statements of the form“ 9 xx=y”(or similarly statements about modes
of being) can appear in statements ofy’s total propositional essence.
I’ve claimed that there is no conceptual incoherence in holding that the essence of
an entity includes its existence, and I’ve shown that the route from this claim to an
ontological proof for the existence of an entity in question is not at all straightfor-
ward. This relieves some of the pressure against a blanket ban on allowing the
existence of an entity to enter into that entity’s essence.
That said, certain metaphysical systems might require a blanket ban. Consider a
kind of Meinongianism on which every object, whether existent or not, has a strict
essence, and this essence consists in all the properties that characterize the object in
question. So, for example, the round square’s strict essence includes that it is round
and square. It is hard to see how the Meinongian can deny that the total propositional
essences of objects are necessarily true: what is contingent is which objects have or
(^87) Oderberg (2007: 128) suggests that having one’s existence included in one’s essence suffices for one’s
being a necessary being. Vallicella (2002: 71) claims that if one’s essence and existence are identical, then
one is a necessary being. The reflections of this section show that at a minimum more premises are needed
before either conclusion can be reached. 88
In light of these remarks, it is worth once again re-examining other classical arguments for the
existence of God. For example, Dasgupta (2016) argues that the Principle of Sufficient Reason implies that
there is some thing (or things) whose essence includes their existence, although he denies that these must
be a God. 89
PaceGeach (2006: 122).