LECTURE 26 NEW VERSIONS OF DESCARTES’ ARGUMENT AND THE LEIBNIZIAN ARGUMENT G.E. MOORE’S OBSERVATION

DESCARTES’ ARGUMENT I CAN CONCEIVE OF THERE BEING NO PHYSICAL BODIES. I CANNOT CONCEIVE THAT I DO NOT EXIST. THEREFORE: I AM NOT A PHYSICAL BODY.

THIS ARGUMENT COMMITS A CERTAIN FALLACY WHICH DOESN’T HAVE A STANDARD NAME WE MIGHT CALL IT “THE FALLACY OF SUBSTITUTING INTO AN INTENSIONAL CONTEXT”. STILL, THE CARTESIAN THOUGHT EXPERIMENT SEEMS TO HAVE SOMETHING TO IT. RECENT ADVOCATES HAVE DROPPED TALK OF “CONCEIVING” AND JUST SPOKEN ABOUT POSSIBILITY.

THE CARTESIAN TYPE ARGUMENT IS NOT DEAD SAUL KRIPKE ARGUED THAT WE CAN SEE THAT PAIN CANNOT BE A PHYSICAL PROCESS BECAUSE, FOR ANY PHYSICAL PROCESS, SAY “STIMULATION OF C-FIBERS”, IT IS POSSIBLE FOR THERE TO BE PAIN AND NO SUCH PROCESS.

SAUL KRIPKE (1940- )

ALVIN PLANTINGA ARGUED THAT IT IS POSSIBLE FOR EACH AND EVERY CELL OF MY BODY TO BE INSTANTANEOUSLY REPLACED AND YET FOR ME TO CONTINUE TO EXIST. IT CANNOT BE SAID THAT MY BODY CONTINUED TO EXIST.

ALVIN PLANTINGA ( )

DAVID CHALMERS ARGUED THAT “PHILOSOPHICAL ZOMBIES” ARE POSSIBLE. SUCH A BEING HAS ALL THE PHYSICAL CHARACTERISTICS OF A PERSON (THE BRAIN IS FUNCTIONING NORMALLY AND NEURONS ARE FIRING) AND YET IT DOESN’T HAVE CONSCIOUSNESS. IF SO, THEN CONSCIOUSNESS IS NOT A PHYSICAL PROCESS.

DAVID CHALMERS ( )

LEIBNIZIAN ARGUMENT AGAINST PHYSICALISM (1)IT IS IMPOSSIBLE THAT PHYSICAL THINGS SHOULD BE CAPABLE OF THOUGHT AND PERCEPTION. (2)I AM CAPABLE OF THOUGHT AND PERCEPTION. THEREFORE:  (3) I AM NOT A PHYSICAL THING

THE LEIBNIZIAN-TYPE OF ARGUMENT IS NOT DEAD PLANTINGA HAS ARGUED THAT WE CAN SEE THAT THINKING AND CONSCIOUSNESS COULD NOT BE PRODUCED BY A PHYSICAL PROCESS. EVEN IF WE CAN’T SEE HOW IT COULD BE PRODUCED IN A NON-PHYSICAL BEING, WE DON’T SEE THAT IT IS IMPOSSIBLE FOR THAT TO HAPPEN. A THIRD ARGUMENT AGAINST PHYSICALISM IS DUE TO G. E. MOORE

G. E. MOORE

A THIRD ARGUMENT THAT A PERSON IS NOT A BODY G. E. MOORE’S OBSERVATION ABOUT “WHERE” HE IS: (1)I AM CLOSER TO MY HANDS THAN I AM TO MY FEET. (2) MY BODY IS NOT CLOSER TO MY HANDS THAN TO MY FEET. THEREFORE (BY DD): (3) I AM NOT MY BODY.

VAN INWAGEN SUGGESTS THAT THIS IMPRESSION IS DUE TO THE FACT THAT OUR SENSE ORGANS (MOSTLY) CLUSTER AROUND THE HEAD HE SPECULATES THAT HELEN KELLER WOULD THINK THAT SHE IS CLOSER TO HER HANDS THAN TO HER HEAD. VAN INWAGEN CONCLUDES THAT NONE OF THESE THREE ARGUMENTS ARE FORCEFUL AGAINST PHYSICALISM.

A FOURTH ARGUMENT AGAINST PHYSICALISM: “ THE SCORPIAN GOO ARGUMENT ” (1)IT IS POSSIBLE FOR THERE TO BE BEINGS THAT ARE PHYSICALLY VERY UNLIKE US (SAY FROM A GALAXY IN THE CONSTELLATION SCORPIO), BUT WHO HAVE THOUGHTS AND FEELINGS AND PERCEPTION. (2) IF THIS IS POSSIBLE, THEN PAIN (FOR EXAMPLE) CANNOT BE A PROCESS THAT OCCURS IN OUR BRAINS – FOR NO SUCH PROCESS OCCURS IN THE SCORPIANS.

OUR BRAIN PROCESSES ARE NECESSARILY NOT “PURPLE GOO” PROCESSES THEREFORE, (3) MENTAL PROCESSES ARE NOT BRAIN PROCESSES.