tain that I no less find
the idea of a God in my consciousness, that is, the idea of a being
supremely perfect, than that of any figure or number whatever: and I
know with not less clearness and distinctness that an (actual and
eternal) existence pertains to his nature than that all which is
demonstrable of any figure or number really belongs to the nature of
that figure or number; and, therefore, altho all the conclusions of
the preceding "Meditations" were false, the existence of God would
pass with me for a truth at least as certain as I ever judged any
truth of mathematics to be, altho indeed such a doctrine may at first
sight appear to contain more sophistry than truth. For, as I have been
accustomed in every other matter to distinguish between existence and
essence, I easily believe that the existence can be separated from the
essence of God, and that thus God may be conceived as not actually
existing. But, nevertheless, when I think of it more attentively, it
appears that the existence can no more be separated from the essence
of God than the idea of a mountain from that of a valley, or the
equality of its three angles to two right angles, from the essence of
a (rectilineal) triangle; so that it is not less impossible to
conceive a God, that is, a being supremely perfect, to whom existence
is wanting, or who is devoid of a certain perfection, than to conceive
a mountain without a valley.

But tho, in truth, I can not conceive a God unless as existing, any
more than I can a mountain without a valley, yet, just as it does not
follow that there is any mountain in the world merely because I
conceive a mountain with a valley, so likewise, tho I conceive God as
existing, it does not seem to follow on that account that God exists;
for my thought imposes no necessity on things; and as I may imagine a
winged horse, tho there be none such, so I could perhaps attribute
existence to God, tho no God existed. But the cases are not analogous,
and a fallacy lurks under the semblance of this objection: for because
I can not conceive a mountain without a valley, it does not follow
that there is any mountain or valley in existence, but simply that the
mountain or valley, whether they do or do not exist, are inseparable
from each other; whereas, on the other hand, because I can not
conceive God unless as existing, it follows that existence is
inseparable from Him, and therefore that He really exists: not that
this is brought about