242 J.J. Haldane
The mathematical model is unsuitable in as much as its existents are abstracta
while God is real; but it is nonetheless useful for bringing out the crucial
contrast between created and uncreated necessity. An entity that is neither
generated out of a prior one nor can perish by natural means, which does not
change and which may exist eternally, can yet be ‘contingent’ in the sense that
its non-existence is possible. In Aquinas’s terms its essence is one thing, its
existence another; and since the former does not entail the latter the fact of
its existing is not self-explanatory. Put in regard to numbers, or angels, even if
they exist praeter-naturally and eternally and cannot cease to exist other than
by Divine annihilation they are not intrinsically existent. What the essence–
existence argument set out earlier shows, I believe, is that the actuality of
things whose essence is not existence is due to the ex nihilo creative causality
of God. Evidently God’s being cannot be caused by something external, but
nor can it be caused by something internal – the latter in part because if it
were, then God would antecedently have been incompletely actual, but more
pertinently this would involve a contradiction: attributing God’s existence to
the efficacy of something pre-existent, namely God’s nature. We should not
say, therefore, as Descartes, Spinoza and others have done, that God is ‘cause
of itself ’ (Deus causa sui), for that requires action prior to existence; and nor
should we say that in some other way God’s existence ‘follows from’ his
essence. Rather God’s essence is existence. As reported in the Hebrew bible,
when Moses asked God his name God said ‘I am who am’ (Exodus 3: 14);
which is to say God is that whose nature is being. This is what it means to
beuncreated necessary being: to be uncaused being itself. Of necessity there
cannot be more than one such, and because it exhibits an essence /existence
distinction the world cannot be necessary in this sense. Pacesome contem-
porary formulations of divine necessity, God is not anecessarybeingexisting
in every possible world, but being itself antecedent to and transcendent of
all created possibiliaandnecessaria.
In light of this one might wonder whether, after all, the Anselmean onto-
logical proof is not sound. For if God’s nature is to be, then an adequate
notion of God’s essence must include reference to his existence; and so from
the very concept of God it follows that God exists. The proper response is
suggested by Aquinas’s oft misunderstood distinction between principles
‘self-evident in themselves’ and principles ‘self-evident to us’. In brief, this
distinguishes between propositions in which that which is predicated of the
subject belongs to it as a matter of de re necessity, and propositions in which
the predicate is included in the definition of the subject de dicto. For example,
while it is not part of the nominal definition of ‘event’ that every event has a
cause, it may yet be true as a matter of metaphysical necessity that every event
is an effect. If so, then while this latter necessity is not evident to us merely in
virtue of grasping the meaning of the term ‘event’, the proposition ‘every