lecture 17 the modal ontological argument (a variant of hartshorne’s version)

LECTURE 17

THE MODAL ONTOLOGICAL ARGUMENT (A VARIANT OF HARTSHORNE’S

VERSION)

MODAL ONTOLOGICAL ARGUMENT

(1) IT IS POSSIBLE THAT THERE BE A PERFECT BEING. [Premise]

(2) NECESSARILY, IF THERE IS SOMETHING THAT IS PERFECT, THEN NECESSARILY THERE IS SOMETHING THAT IS PERFECT. [Premise]

(3) IT IS POSSIBLE THAT IT IS NECESSARY THAT THERE IS A PERFECT BEING.

[(1), (2), MMP].

THERE IS A NECESSARILY EXISTING BEING!

(4) IT IS NECESSARY THAT THERE IS A PERFECT BEING. [(3),S5] (CONCLUSION)

SO FROM PREMISES (1) AND (2), WE CAN VALIDLY DEDUCE THAT THERE IS A NECESSARILY EXISTING BEING.

Q: WHY IS THERE SOMETHING RATHER THAN NOTHING?

A: IT IS NECESSARILY THE CASE THAT SOMETHING EXISTS.

IS THE ARGUMENT DEDUCTIVELY VALID?

• THERE MAY BE SOME DOUBT ABOUT THE LOGIC USED, ESPECIALLY (S5). I HERE RECORD MY CONVICTION THAT THE ARGUMENT IS DEDUCTIVELY VALID. YOU CAN JUDGE FOR YOURSELF IF YOU TAKE PHIL 186.

DIGRESSION ON HARTSHORNE’S VERSION

TRANSLATIONS FOR THE LOGICALLY CHALLENGED:P(x): x is perfect.(x)(…x…): There is something x such that …x… .… ---: If …, then ---.N…: It is necessary that … .…: not… (or “It is not the case that….”)...--- : Either … or --- .

HARTSHORNE’S VERSION IS (ALMOST)VALID

HARTSHORNE’S PREMISE (1) IS ALMOST THE SAME AS OUR PREMISE (2). HE ACTUALLY USES OUR VERSION IN ONE OF HIS INFERENCES (CORRECTION). HARTSHORNE’S PREMISE (5) IS EQUIVALENT TO OUR PREMISE (1):

(5) IT IS NOT NECESSARILY NOT THE CASE THAT THERE IS A PERFECT BEING.

WITH THE ONE CORRECTION, THIS ARGUMENT IS VALID – AND USES ESSENTIALLY THE SAME ASSUMPTIONS THAT WE USED.

YES, BUT ARE THE PREMISES TRUE?

CONSIDER ONLY OUR VERSION.PREMISE (2) IS OFTEN OMITTED AND SECURED BY

DEFINITION.WE CAN DEFINE A PERFECT BEING AS ONE THAT

HAS EVERY PERFECTION – INCLUDING NECESSARY EXISTENCE.

NOTICE THAT THIS VERSION DOES NOT COMMIT THE FALLACIES WE NOTED CONCERNING DESCARTES’ VERSION.

PREMISE (2) SEEMS TRUE

EVEN IF WE DON’T DEFINE ‘PERFECT BEING’, IT IS VERY PLAUSIBLE THAT IF SUCH A BEING EXISTED, THEN IT WOULD NECESSARILY EXIST.

AN OBJECTION

THE AGNOSTIC MAY TAKE THE POSITION THAT IT IS POSSIBLE THAT A PERFECT BEING EXISTS AND IT IS POSSIBLE THAT SUCH A BEING DOES NOT EXIST.

BUT USING OUR PREMISE (2), IT FOLLOWS FROM THE ASSUMPTION THAT IT IS POSSIBLE THAT SUCH A BEING DOES NOT EXIST THAT (NECESSARILY) SUCH A BEING DOES NOT EXIST!

THE RESPONSE TO THIS OBJECTION LEADS TO ANOTHER

THE PREMISE ‘IT IS POSSIBLE THAT THERE BE A PERFECT BEING’ DOES NOT MEAN ‘FOR ALL I KNOW THERE IS A PERFECT BEING’. THIS LATTER IS A KIND OF EPISTEMIC POSSIBILITY. THE AGNOSTIC IS SAYING: I DON’T KNOW THAT THERE ISN’T ONE AND I DON’T KNOW THAT THERE IS.’ THIS IS PERFECTLY COHERENT.

WHAT DOES PREMISE (1) MEAN?

PREMISE (1) MEANS THAT IT IS ABSOLUTELY POSSIBLE THAT THERE BE SUCH A BEING. AT THE VERY LEAST IT IMPLIES: THERE IS NO CONTRADICTION LURKING IN THE IDEA OF A PERFECT BEING.

THAT A PROPOSITION IS POSSIBLE (NOT CONTRADICTORY) IS NOT ALWAYS SO EASY TO KNOW.

GAUNILO RETURNS(AND THIS TIME HE’S ANGRY)

DEFINE A NEARLY PERFECT BEING AS ONE THAT HAS EVERY PERFECTION EXCEPT FOR ONE MORAL VIRTUE. THEN THE PREMISES CORRESPONDING TO OUR (1) AND (2) SEEM JUST AS REASONABLE IN THIS CASE. SO WE CONCLUDE THAT THERE IS ALSO A NEARLY PERFECT BEING. WE CAN CONTINUE IN THIS WAY AND ‘PROVE’ THE EXISTENCE OF MANY SLIGHTLY DEFECTIVE NECESSARY BEINGS!

THE MODAL ONTOLOGICAL ARGUER’S REMAINING RESPONSE

THE DEFENDER OF THIS MODAL ONTOLOGICAL ARGUMENT NEEDS TO SHOW THAT HIS PREMISE (IT IS POSSIBLE THAT THERE IS A PERFECT BEING) IS MORE, PERHAPS MUCH MORE, REASONABLE THAN THE CORRESPONDING PREMISES OF THE GAUNILO-ARGUMENTS.

THERE IS SOME REASON TO THIS THAT THIS CAN BE DONE. THE MODAL ONTOLOGICAL ARGUMENT IS NOT DEAD.

WE MIGHT CONCLUDE THAT, IN ANY CASE, THIS IS NOT A PROOF OF THE

NECESSARY EXISTENCE OF SOMETHING

WE TURN TO AN ATTEMPT TO SHOW THAT SINCE THERE ARE CONTINGENT BEINGS, THERE HAS TO BE A NECESSARY BEING TO EXPLAIN THAT FACT: THE (OR A) COSMOLOGICAL ARGUMENT. (BEGIN READING CHP. 7)