4 - Descartes' Conceivability Argument

Argument for substance dualism

what does Descartes describe when he points out how he thinks of his mind and body in his premises

he has a clear and distinct idea of himself as something that thinks and isn’t extended, and of his body as something that doesn’t think and is extended

according to Descartes, if he has a clear and distinct idea of something….

God can create it the way it corresponds to his thoughts

what conclusions does Descartes come to via his conceivability argument

God created the mind and body as Descartes’ conceived, mind and body exist independently, they are distinct substances

how can we simplify Descartes’ conceivability argument

it is conceivable the mind can exist without a body, therefore this is possible, therefore they are distinct substances

what issue is there with Descartes’ conceivability inference

he infers possibility from conceivability

what other assumption does Descartes make in his argument

the mind can exist without the body

how does philosophical behaviorism counter Descartes’ ideas about the mind existing without a body

interprets the mind via desires and actions, and these cannot happen without a body

what being relies on the idea that there are minds without bodies

God

why is Descartes’ argument about conceivability weak

we can make mistakes about what is conceivable

but Descartes accepts that we can be mistaken in what we conceive, so what idea of his do we need to challenge

clear and distinct ideas

is there a difference between whats conceivable and metaphysically possible

yes

laws of nature, such as gravity, define what is ….

physically possible

what can we think of conceptual possibilities as

logical possibilities

are the laws of nature contingent (they could have been otherwise)

yes

if something is physically impossible, it could still be …

logically possible/conceivable (e.g. the speed of light being faster)

‘water is H2O’ is not analytically true, so ….

its logically possible water is not H2O

but, water and H2O are the same thing. They are two concepts but one property, so metaphysically

its metaphysically impossible for water to be anything other than H2O

so, just because it is logically possible that the mind and body are separate, does not mean that it is

metaphysically possible

how does Descartes defend against the metaphysical possibility counter

its a clear and distinct idea

if a mind is something that thinks, and a body is something that is extended, do these statements exclude each other (e.g. a mind can’t think and have extension)

no

what could we think of thought and extension as

properties of the same substance

so, if Descartes is right about clear and distinct ideas, …

it is metaphysically possible that the mind and body are separate substances or the same substance

if Descartes managed to prove it was metaphysically impossible for mind and body to be the same substance, would he succeed in proving substance dualism

yes