Problem of Interaction
Descartes argues that the mind and the body must be separate as they are two different substances which are incompatible
The essence of the body is the extension of physical space
The essence of the mind is non physical thought
use of Lebinez principle
Whilst the physical body can be separated, the mind cannot further suggesting they are two incompatible sources.
However:
Elizabeth of Bohemia raises the issue on interaction- for two things to interact they must have two sides two clash which therefore produces interaction- if the mind is non physical then how is it supposed to interact with a physical body (eg like a ghost riding a bike) Descartes doe not provide a sufficient explanation for this- attempting to argue the pineal gland is the reason for this as the pineal gland is in the physical body as is cabals of single thoughts- the link between the mind and the body- however this is still using the physical as an explanation for the mind
Zinn argues that a dogs brain is is fully divisible
Therefore- Descartes fails to explain the correlation between the mental and the physical.
Logical Privacy
Descartes began to doubt that his body was real[ the mind and body must be separate as he could imagine his mind without a body - could imagine losing a foot, an arm or some other part of his anatomy- suggested that this would not reduce his soul/mind in any way
He could not deny his mind as “i think therefore i am”- could not doubt his mind- suggested he could be being deceived by a devil however he has an image of God is his mind which could not deceive him
The concept of God in his mind relies on his mental faculties being right and that God was not some evil deceiver
Furthermore- logical privacy- how do we know that others also have minds- all we can see is the physical- JS Mill- the mind/body interact in a law like way- must exist
However- we can never know for sure- all we will ever see/know is the persons physical body/acts/words-
The criticisms of Gilbert Ryle
Gilbert Ryle argues that Descartes is in grammatical error (a category error) when he speaks of the soul/mind as a separate substance
The example of the university student- nothing more than to what we see
The mind is like a ghost in the machine- an extra entity is attributed when none is needed- mental/physical events are not distinct in this view
Ryle suggests that way we can the mind are dispositions of our body
The mind is the the intelligent dispositions of your body
Conclusion:
Ultimately Descartes argument fails to be persuasive as we are unable to verify the argument and fails to answer key questions on interaction- Descartes can therefore be accused of using his theory to fit the facts rather than proving anything