LECTURE 15
DESCARTES’ VERSION
OF
THE ONTOLOGICAL
ARGUMENT
A METAPHYSICAL QUESTION
Q: “WHY IS THERE ANYTHING AT ALL, RATHER
THAN NOTHING?”
(1) EMPTY SPACE IS SOMETHING (NOT
NOTHING)
(2) A QUANTUM VACUUM IS SOMETHING (NOT
NOTHING).
DESCARTES’ VERSION
(D1) A PERFECT BEING HAS ALL PERFECTIONS.
(D2) EXISTENCE IS A PERFECTION.
(C1) A PERFECT BEING HAS EXISTENCE.
(C2) A PERFECT BEING EXISTS
HERE IS THE ANSWER TO THE QUESTION:
Q: “WHY IS THERE ANYTHING AT ALL?”
A: “THE STATEMENT THAT THERE IS NOTHING
AT ALL IS CONTRADICTORY. THERE HAS TO BE
A PERFECT BEING. HERE IS A PROOF FROM
NECESSARILY TRUE PREMISES.”
THIS VERSION EITHER BEGS THE
QUESTION OR IS DEFECTIVE
BECAUSE OF AN EQUIVOCATION
BEGGING THE QUESTION: AN ARGUMENT (OR
ARGUER) COMMITS THE FALLACY OF
BEGGING THE QUESTION IF ONE OF
THE PREMISES OF THE ARGUMENT COULD
NOT BE KNOWN (OR REASONABLY BELIEVED)
WITHOUT ALREADY KNOWING (OR
BELIEVING) THE CONCLUSION.
HERE IS A STANDARD EXAMPLE OF
BEGGING THE QUESTION
(B1) THE BIBLE SAYS THAT GOD
EXISTS.
(B2) EVERYTHING THAT THE
BIBLE SAYS IS TRUE.
 (B3) GOD EXISTS.
BUT WHY BELIEVE PREMISE (2)?
ARGUMENT JUSTIFYING PREMISE (2):
(B0) GOD (EXISTS AND) IS ALL
KNOWING AND ALL GOOD.
(B1*) THE BIBLE IS THE WORD OF
GOD.
 (B2) EVERYTHING THAT THE BIBLE
SAYS IS TRUE.
THESE ARGUMENTS ARE BOTH
DEDUCTIVELY VALID!
THE PROBLEM WITH THE OVERALL ARGUMENT
(CONSISTING OF THE TWO ARGUMENTS
TOGETHER) IS NOT THAT THEY ARE NOT
VALID. THEY ARE BOTH VALID.
THE PROBLEM IS EPISTEMIC. THE ARGUMENTS
TOGETHER ARE WORTHLESS. IF YOU ARE
ALREADY JUSTIFIED IN BELIEVING (B0), THEN
THE REST OF THE ARGUMENT IS
SUPERFLUOUS. IF YOU ARE NOT, THEN THE
ARGUMENT OVERALL IS NOT COGENT.
BUT HOW, EXACTLY, DOES
DESCARTES’ ARGUMENT COMMIT
THIS FALLACY?
THE LOGICAL SITUATION IS A LITTLE BIT
COMPLICATED. THE ARGUMENT, AS STATED,
COMMITS ANOTHER FALLACY: THE FALLACY
OF EQUIVOCATION. WHEN WE REMOVE THE
EQUIVOCATION, WE GET TWO ARGUMENTS:
ONE OF THEM BEGS THE QUESTION AND THE
OTHER DOESN’T HAVE THE CONCLUSION
CLAIMED.
EQUIVOCATION
AN ARGUMENT (OR ARGUER) COMMITS THE
FALLACY OF EQUIVOCATION IF
THERE IS A SINGLE TERM OR PHRASE THAT IS
USED WITH TWO DIFFERENT MEANINGS SO
THAT THE ARGUMENT IS INVALID [AND IF WE
ASSSIGN THE SAME MEANING FOR BOTH
TERMS THE RESULTING ARGUMENTS HAVE
OTHER DEFECTS].
EXAMPLE OF EQUIVOCATION
(1) THE END OF A THING IS ITS AIM.
(2) DEATH IS THE END OF LIFE.
 (3) DEATH IS THE AIM OF LIFE.
AT ONE OCCURRENCE, “END” MEANS THE
PURPOSE OF SOMETHING.
AT THE OTHER, “END” MEANS THE
TERMINATION OF SOMETHING. WITH THESE
MEANINGS, IT IS INVALID.
DESCARTE’S VERSION
(D1) A PERFECT BEING HAS ALL PERFECTIONS.
(D2) EXISTENCE IS A PERFECTION.
(C1) A PERFECT BEING HAS EXISTENCE.
(C2) A PERFECT BEING EXISTS
SOMETIMES “A SO-AND-SO” MEANS “THERE IS
(EXISTS) A SO-AND-SO AND IT….”
SOMETIMES “A SO-AND-SO” MEANS “ALL THE
SO-AND-SO’s ARE…(OR ‘EVERY SO-AND-SO’) IS
…”
“A PERFECT BEING”
COMPARE:
(1) A SCOUT IS LOYAL.
(2) A HOMELESS PERSON ASKED ME FOR
MONEY.
THE PHRASE “A SCOUT” DOES NOT IMPLY THAT
THERE IS A SCOUT (LOYAL OR NOT).
THE PHRASE “A HOMELESS PERSON” IMPLIES
THAT THERE EXISTS A HOMELESS PERSON (HE
ASKED ME FOR MONEY)
VERSION ONE: EQUIVOCATION
REMOVED
(D1’) ALL THE PERFECT BEINGS (THAT THERE
ARE, IF ANY) HAVE ALL PERFECTIONS.
(D2) EXISTENCE IS A PERFECTION.
(C1’) ALL THE PERFECT BEINGS (THAT THERE
ARE) HAVE EXISTENCE.
(C2’) ALL THE PERFECT BEINGS (THAT THERE
ARE) EXIST.
THE CONCLUSION IS NOT WHAT IS WANTED.
VERSION TWO: EQUIVOCATION
REMOVED.
(D1”) THERE IS (EXISTS) A PERFECT BEING
HAVING ALL PERFECTIONS.
(D2) EXISTENCE IS A PERFECTION.
(C1”) THERE IS (EXISTS) A PERFECT BEING THAT
HAS EXISTENCE.
(C2”) THERE IS (EXISTS) A PERFECT BEING THAT
EXISTS.
THIS VERSION BEGS THE QUESTION.
ALAS, DESCARTES’ ATTEMPT TO
PROVE THAT THERE IS A
NECESSARY BEING FAILED
BUT THERE IS A MODERN ‘VERSION’ OF THE
ONTOLOGICAL ARGUMENT THAT COMMITS
NO LOGICAL FALLACIES AND WHICH MAY
EVEN BE COGENT (!).