Parody and Possibility
Leibniz's argument does seem vulnerable to parody (Adams 1994, 150–51). Nothing he
says indicates that his simple perfections entail one another. And it's hard to see how he
could allow this. If omniscience did entail omnipotence, say, it would not be in virtue of
“containing” the negation of nonomnipotence (since it doesn't contain the negation of any
property). If the perfections do not entail each other, it seems possible to conjoin all save
omniscience with almost-omniscience. For as none contain the negation of any other
property, none contain the negation of almost-omniscience. But then the other perfections
are consistent with almost-omniscience—or at least Leibniz's argument gives us as much
reason to think this as to think that the perfections are all consistent. And so the argument
gives us as much reason to grant the possibility of a necessarily existing almost-
omniscient almost-God as we do the existence of God. But they can't both be possible.
Just because we do see that it is vulnerable to parody, it's clear that Leibniz has a problem
with the gap between consistency and real metaphysical possibility. The concepts of God
and almost-God are equally consistent, on his showing. But it cannot be that both are
possible, for at most one of these beings really exists. So we can't take Leibniz to have
shown that it is possible that God or an absolutely perfect being exists.
Kant
Kant's Critique of Pure Reason ([1781] 1956) is often treated as the death knell of
arguments from perfection. Kant claimed against Descartes that “ `being' isnota
predicatewhich could be added to the concept of a thingIt is merely the positing of a
thing” (A598/B626). This denies (30), at least if we assume that every perfection is
expressed by a “predicate,” something that describes or characterizes an object. On this
assumption, it is very nearly one of Gassendi's moves. Kant also argued this way:
end p.106
- All necessary truths are really conditional in form (“The absolute necessity of the
judgment is only a conditioned necessity ofthe predicate in the judgment” [A703–
4/B621–22]). - Any conditional expansion of a purported necessary existential truth would be
analytic as well as existential. - There are no analytic existential propositions (A708/B626).^9
- So no necessary proposition asserts the existence of anything.
(36) and (37) follow Hume. But Kant's way of supporting them is, for better or worse, his
own. If (36) or (37) is true, then Descartes' argument cannot be sound, if its contention is
in effect that “God exists” is analytic. If an argument is unsound, it either has a false
premise or makes an invalid inference, and one who asserts that an argument is unsound
must back the claim by showing one or the other. Kant's denial of (30) does this.