FREE ESSAY ON DIVISIBILITY ARGUMENT

DIVISIBILITY ARGUMENT

DIVISIBILITY ARGUMENT
This paper will discuss the dualism's Divisibility Argument. This argument relies on
Leibniz's Law and uses a different property to prove the distinctness of brain states of
mental states. Mary, who is a materialist, presents several objections to that argument.
Her main objection corresponds to the first/third-person approach. She believes that Dave
presents that argument only from the first-person approach, which is introspection, and
totally disregards the third-person approach, which is observation of another mind.
Mary's objections will follow by the Dave's response on them from the dualist's point of
view.
The purpose of the Divisibility Argument is to prove that mental states are different
from the brain states. My body, which includes my brain, is divisible. However, I cannot
conceive of my mind as divisible. Therefore, my mind is distinct from any part of my
body.
Descartes was the first who established the Divisibility Argument. He held that the two
components which constitute man had an independent origin and are of a fundamentally
different nature. The body is divisible, since it can be separated for example, my leg or
my hand can be cut off; my brain can be cut on half. However, the idea of the divisible
mind is inconceivable. 
This argument relies on the Leibniz's Law. It is a principle about identity, which says,
"if an object or event X is identical with an object or event Y, then X and Y have all of
the same properties." So if X and Y have any different properties, then X can not be
identical with Y. Divisibility Argument uses a different property to prove the
distinctness of brain states and mental states: the property of being indivisible. In
this case, the mind has a property and brain lacks it. The body can be divided, however,
it cannot be done with the mind.
Mary has several objections to this argument. First, she believes that the mind is an
entity, which is composed of several mental states: thoughts, beliefs, memories, desires,
etc. Mary strongly disagrees with Descartes' claim that the mind employs itself in its
different properties: willing, desiring, understanding, and so on. Secondly, she
clarifies the meaning of the word "conceive" in the Dave's argument. The term "conceive"
might mean either "imagine" or "understand." Imagining literally involves "forming an
image of" or "picturing" in one's mind, whereas understanding is more "conceptual" and
does not require the ability to picture something. In case, Dave interprets the word
"conceive" as "imagine" in the second premise of the argument, this premise becomes
untrue. The fact that he cannot imagine something to be the case does not make it true in
everyone's case. Different minds can imagine different things. However, if Dave implies
"understand" as a meaning of "conceive" the second premise still remains doubtful. The
fact that Dave cannot understand it does not exclude the possibility that someone else is
capable to think of his mind as having parts.
The next major objection to the Divisibility Argument concerns first/third-person
approach. Mary rejects Dave's assumption that the true nature of the mind can be
understood solely through introspection or from the first-person approach. She claims
that things that cannot be conceived through the first-person approach, which is
introspection, can be understood or investigated through the third-person approach, which
is observation and science. Therefore, even if it is true that the mind cannot be
conceived as divided from the first-person perspective, it is possible that it would be
the opposite from the third-person perspective. The perfect example of that case is the
multiple personality disorder. This is the clear case where the third-person perspective
reveals the true nature of a mind as divided regardless of how it seems from the
first-person perspective.
As a response to Mary's objection, Dave agrees that the second premise in the argument
does not have always a true value that makes the argument unsound. Therefore, he changes
it to "I cannot conceive of my individual mental states as having parts." In the case of
the first/third-person approach, Dave relates to the multiple personality disorder as a
case with several minds rather than one divided mind. 
In my opinion, Dave does not satisfactorily respond to the Mary's objections since he
does not give a good reasoning for his point of view. However, I do believe that the mind
is indivisible since there is no such thing as part of mind. Mind and matter have
fundamentally different natures: matter, which is extended, divisible, passive, and
law-like; and mind, which is unextended, indivisible, active, and free. I definitely
agree with Descartes that the soul occupies the whole body in all its parts, so the
reduction of the body in any way does not reduce the soul. Thoughts, feelings, desires
and so on, are all properties of the mind but not its parts.