Substance Dualism

What is substance dualism?

theory that human beings are composed of two distinct substances (res extensa- physical substances and res cogitans- mental substances). the mind and body are independent of one another.

define substance

a thing which can exist on its own without depending on anything else to exist

what are the two arguments in support of substance dualism?

the conceivability argument

the divisibility argument

who created the arguments in support for substance dualism?

descartes

what is the indivisibility argument?

uses Leibniz’s Law which states if two things share all the same properties, they are one thing. if one thing has even one property which the other lacks, they are two distinct things

my mind is indivisible

my body is divisible

my mind and body do not share all the same properties

so my mind and body are two distinct things

what are the criticisms to the indivisibility argument?

the mental is divisible ( DID and HUME)

not everything physical is divisible

what is the criticism to the indivisibility argument based on the menatl being divisible?

dissociative identity disorder is a condition where one mind has multiple identities so it can be argued this shows that the mind is divisible.

HUME: self is a bundle of perceptions

we only experience a bundle of perceptions but never actually experience an actual self

so i am nothing more than just a bundle of perceptions

so the mind is not a singular entity but rather a collection of perceptions

these perceptions are distinct from one another so the mind is divisible

what is the criticism to the indivisibility argument based on not everything physical is divisible?

if you keep dividing your body, you eventually get to a point where you can no longer divide it eg you get to a string of energy

so it is possible for the physical to be indivisible

so just because the mind is indivisible, it doesn’t mean it can’t be a physical substance

define logically possible

what is possible without contradictions, they are possibilities consistent with the laws of thought

define physical possibility

possibilities consistent with the laws of physics

define metaphysically possible

logical possibilities which are physically impossible and logical possibilities that are physically possible, what is possible in all possible words

what is the relation between logical and metaphysical possibility?

any logical impossibility is a metaphysical impossibility

what is the conceivability argument?

if i can clearly and distinctly conceive of the essential natures of two things separately, it must be metaphysically possible to separate them

i clearly and distinctly perceive myself to be essentially a thinking and unextending thing

i clearly and distinctly perceive my body to be essentially a non-thinking and extended thing

it must be metaphysically possible for mind and body to be separated meaning they are distinct substances

what are the criticisms to the conceivability arguments?

being conceivable doesn’t mean being metaphysically possible

masked man fallacy

mind without body is not conceivable

what philosopher is behind the being conceivable doesn’t mean being metaphysically possible argument?

ARNAULD

what philosopher is behind the mind without body is not conceivable criticism?

HUME

what is the being conceivable does not mean being metaphysically possible criticism and its counter argument?

it is possible for someone who is unaware of the Pythagoras theorem to conceive of a right angle triangle where a2 + b2 = c2 is not the case

it is logically impossible for a right angle triangle to not follow the Pythagoras theorem

so just because it is conceivable , it doesn’t make something metaphysically possible like the conceivability argument claims

CA: in the analogy the person does not know the whole truth about right angle triangles which is why they can conceive of the metaphysically impossible

descartes argues he does know the whole truth of the mind and body so he can’t conceive the metaphysically impossible when it comes to them

What is the masked man fallacy?

i conceive of batman as a caped crusader

i conceive of bruce wayne as a billionaire who is not a caped crusader

so batman is not bruce wayne

this shows a conclusion which is metaphysically possible but not possible in our world as we know that bruce wayne is batman

so the conceivability argument which has the same layout as the masked man fallacy could lead us to a metaphysically possible conclusion that is not possible in our world so it doesn’t prove substance dualism

what is the mind without body is not conceivable criticism?

Hume argues genuine concepts must originate from sense experience

dualists claim the mind is immaterial and unextended

if i had no body and just my mind, i would have nothing material or extended

without anything material or extended, i have no sense experience

so a mind without body would lack meaning or genuine concepts meaning it would not be conceivable