Metaphysics of mind
DUALISM
2 kinds of thing
Substance
2 diff kinds of substance in universe:
● Mental
● Physical
Minds can exist independently of physical stuff
Eg. a soul is non-physical
Descartes’ conceivability argument
Conceivable for mind and body to exist separately
Responses
Behaviourism: mind without body is inconceivable
To have mental states is to have behavioural dispositions
= to be disposed to move body in certain ways
= inconceivable if no body = also to have mental states without body
, 2
Mind being independent of body may be conceivable / logically possible (no
contradiction), but it might not be physically possible
Masked man fallacy
this argument is fallacious because it switches from talking about ideas to talking about
things themselves = sometimes our ideas are mistaken and reality is different from our
idea of it
Divisibility argument
● Body is divisible
● Mind is not divisible (can’t have ½ a thought)
→mind & body are separate things
Responses
Cases of mental illness in which mind does seem divided
Eg. DID (multiple personality disorder)
Corpus callosotomy: surgical procedure for epilepsy where main connection btw left +
right hemispheres is severed = side effects where diff thoughts from diff hemispheres
= dividing brain can in fact divide the mind
Not everything physical is divisible: even if mind is indivisible, this does not necessarily
prove mind is separate = might be indivisible type of physical substance
Reach point where physical matter becomes indivisible, then not everything that is
indivisible is non-physical
even if Descartes successfully shows that the mind is indivisible, this doesn’t prove that
the mind is non-physical
Problems
Each of us experiences own thoughts, feelings, sensations..
Infer from others’ bhv that they have a mind that causes their bhv
What grounds to make this assumption: possible to have physical bhv without physical
mind so what evidence to find to prove other minds exist at all
DUALISM
2 kinds of thing
Substance
2 diff kinds of substance in universe:
● Mental
● Physical
Minds can exist independently of physical stuff
Eg. a soul is non-physical
Descartes’ conceivability argument
Conceivable for mind and body to exist separately
Responses
Behaviourism: mind without body is inconceivable
To have mental states is to have behavioural dispositions
= to be disposed to move body in certain ways
= inconceivable if no body = also to have mental states without body
, 2
Mind being independent of body may be conceivable / logically possible (no
contradiction), but it might not be physically possible
Masked man fallacy
this argument is fallacious because it switches from talking about ideas to talking about
things themselves = sometimes our ideas are mistaken and reality is different from our
idea of it
Divisibility argument
● Body is divisible
● Mind is not divisible (can’t have ½ a thought)
→mind & body are separate things
Responses
Cases of mental illness in which mind does seem divided
Eg. DID (multiple personality disorder)
Corpus callosotomy: surgical procedure for epilepsy where main connection btw left +
right hemispheres is severed = side effects where diff thoughts from diff hemispheres
= dividing brain can in fact divide the mind
Not everything physical is divisible: even if mind is indivisible, this does not necessarily
prove mind is separate = might be indivisible type of physical substance
Reach point where physical matter becomes indivisible, then not everything that is
indivisible is non-physical
even if Descartes successfully shows that the mind is indivisible, this doesn’t prove that
the mind is non-physical
Problems
Each of us experiences own thoughts, feelings, sensations..
Infer from others’ bhv that they have a mind that causes their bhv
What grounds to make this assumption: possible to have physical bhv without physical
mind so what evidence to find to prove other minds exist at all
