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St. Anselm's Ontological Argument in a Nutshell
St. Anselm of Canterbury (1033-1109) was a monk and theologian who, in his Proslogion, gave an argument for the
existence of God on the basis of the definition of God—i.e., on the basis of what it would mean to be God.
The argument is fatally flawed and should convince no one, but, somewhat surprisingly, it has supporters even to
this day. St. Anselm’s ontological argument for the existence of God runs about like this: (1) God is that greater
than which none can be conceived; (2) an existent God would be greater than a nonexistent God; (3) if God did not
exist, then something greater could be conceived of—namely, a God that did exist; (4) therefore, God exists.
Although it is possible to analyze this argument in some detail, I’ll just give the main problem here. The argument
fails to distinguish between an object or entity and the mental conception of an object or entity.
(A lion wandering
the African savannah isn’t the same as my mental conception of it; the former is a solid object, while the latter is
only an idea.) It might be that an object God would be greater than its mental conception, or that it would be greater
for both the object God to exist and the mental conception of God to be conceived than it would be for the mental
conception of God to be conceived without the object God’s existing; but the conception of God may be the greatest
conceivable conception either way. The object God’s existence or nonexistence doesn’t affect its mental conception’s
being the
greatest possible mental conception. One conceives mental conceptions, but conceives of
objects. One may say, "The concept of God is that concept greater than which
none can be conceived," or one may say, "God is that object the conception of which is greater than the conception of any
other object"; but to say, "God is that greater than which none can be conceived," as St. Anselm does, illegitimately
equates the object
God with its conception. Paying proper attention to the difference between an existing object
and the mental conception of an object makes that problem go away, but it also completely nullifies the argument.
“God is that
entity whose mental conception is the greatest possible,” together with, “An existent God is greater than its mental
conception,” doesn’t lead to a contradiction if God is assumed not to exist.
Had St. Anselm argued that the conception of God is the greatest conceivable
mental conception, and that the conception of God as existent would be greater than the conception of God as nonexistent,
so that the conception of God must be conceived as existent, I’d've had no problem with the argument—but it wouldn’t
have established God’s existence. I conceive of Pegasus as winged, as maned, as white, as solid, as
physical—as existent—but I do not thereby bring Pegasus into existence; and I may conceive of Pegasus as giving a ride
to my nephew instead of to Bellerophon—I may conceive of Pegasus as nonfictional rather than as fictional—but, again, I
do not thereby bring Pegasus into existence. Conceiving of God as existent is not the same as affirming God’s existence;
neither being conceived of as having existence-implying properties nor being conceived of as nonfictional implies actual
existence.
(© 2007 by Keith Brian Johnson)
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