9/11/14
Substances and Attributes
•  Two criteria for substances:
–  A substance is something in which properties
"inhere"; that is, it is what has, or exemplifies,
properties.
–  “The notion of a substance is just this -- that it can
exist by itself, that is without the aid of any other
substance.”"
•  Attributes, “modes”:
–  Properties
–  Relations
•  These can have instances; can be exemplified.
1
Cartesian Substance Dualism
1.  There are substances of two fundamentally different
kinds in the world, minds and bodies.
• 
• 
The essential nature of a body is to be extended in space.
The essence of a mind is to think and engage in other
mental activities.
2.  A human person is a composite being ("union," as
Descartes called it) of a mind and a body.
3.  Minds are diverse from bodies; no mind is identical
with a body.
4.  Minds and bodies causally influence each other.
Some mental phenomena are causes of physical
phenomena and vice versa.
2
1
9/11/14
Transparency of the Mind:
Our minds are completely transparent to us!
•  Self-intimation: Mental states are self-intimating in that =
–  If S is in mental state M then S know that S is in M
•  Incorrigibility (or, infallibility): We are incorrigible about our
own mental states in that =
–  If S believes that S is in mental state M then S is in M.
•  Self-intimation + Incorrigibility = Transparency
3
3 Epistemological Arguments for Mind ≠ Body
1.  Direct or Immediate Knowledge (Indubitability).
2.  Infallibility and Transparency (SeIf-Intimacy).
3.  Privacy, or First-Person Privilege.
4
2
9/11/14
Epistemological Arguments for Substance Dualism - 1
Indubitability
Argument 1
• 
• 
• 
• 
I am such that my existence cannot be doubted.
My body is not such that its existence cannot be doubted.
Therefore, I am not identical with my body.
Therefore, the thinking thing that I am is not identical with
my body.
5
Epistemological Arguments for Substance Dualism - 2
Infallibility and Transparency (SeIf-Intimacy).
Argument 2
•  My mind is transparent to me -- that is, nothing can be in
my mind without my knowing that it is there.
•  My body is not transparent to me in the same sense.
•  Therefore, my mind is not identical with my body.
6
3
9/11/14
Epistemological Arguments for Substance Dualism - 3
Privacy, or First-Person Privilege
Argument 3
•  Each mind is such that there is a unique subject who has
direct and privileged access to its contents.
•  No material body has a specially privileged knower -knowledge of material things is in principle public and
intersubjective.
•  Therefore, minds are not identical with material bodies.
7
Problem with Epistemic/Intentional Properties
• 
• 
• 
• 
Mark Twain is known by me to be a writer
Samuel Clemens is not known by me to be a writer
So, one has a property that the other lacks
Therefore, Mark Twain ≠ Samuel Clemens
8
4
9/11/14
Leibniz Law
Leibniz Law is the conjunction of the following two principles:
The Indiscernibility of Identicals:
•  If two things are identical, then they share all their
attributes (metaphysical truth)
The Identity of Indiscernibles is the converse of this:
•  If two things share all their properties then they are
identicals (controversial claim)
•  Leibniz Law should be so stated that it is not falsified by
epistemic/intentional properties, or;
•  The ontological status of inverse epistemic/intentional
properties should be understood to be moot.
9
Metaphysical Arguments for Substance Dualism 1
•  Argument 4
•  My essential nature is to be a thinking thing.
•  My body's essential nature is to be an extended thing in
space.
•  My essential nature does not include being an extended
thing in space.
•  Therefore, I am not identical with my body. And since I am
a thinking thing (namely a mind), my mind is not identical
with my body.
10
5
9/11/14
Metaphysical Arguments for Substance Dualism 2
•  Something is "essentially" or "necessarily" F, where F
denotes a property, just in case whenever or wherever (in
any "possible" world) it exists, it must be F.
Argument 5
•  If anything is material, it is essentially material.
•  However, I am possibly immaterial-that is, there is a world
in which I exist without a body.
•  Hence, I am not essentially material.
•  Hence, it follows (with the first premise) that I am not
material.
11
Metaphysical Arguments for Substance Dualism 3
Argument 6
• 
• 
• 
• 
Suppose I am identical with this body of mine.
In 1995 I existed.
In 1995 this body did not exist.
Hence, from the first premise, it follows that I did not exist
in 1995.
•  But this contradicts the second premise, and the
supposition is false.
•  Hence, I am not identical with my body.
12
6
9/11/14
Metaphysical Arguments for Substance Dualism 4
(NI) If X = Y, then necessarily X = Y -- that is, X = Y in every
possible world.
Argument 7
•  Suppose I am identical with this body of mine.
•  Then, by (NI), I am necessarily identical with this body —
that is, I am identical with it in every possible world.
•  But that is false, for
–  (a) in some possible worlds I could be disembodied and
have no body, or at least
–  (b) I could have a different body in another possible world.
•  So it is false that I am identical with this body in every
possible world, and this contradicts the second line.
•  Therefore, I am not identical with my body.
13
Descartes’ Conceivability Argument in Med 6
“And first of all, because I know that all things which I apprehend clearly and distinctly
can be created by God as I apprehend them, it suffices that I am able to apprehend
one thing apart from another clearly and distinctly in order to be certain that the one is
different from the other, since they may be made to exist in separation at least by the
omnipotence of God; and it does not signify by what power this separation is made in
order to compel me to judge them to be different: and, therefore, just because I know
certainly that I exist, and that meanwhile I do not remark that any other thing
necessarily pertains to my nature or essence, excepting that I am a thinking thing, I
rightly conclude that my essence consists solely in the fact that I am a thinking thing [or
a substance whose whole essence or nature is to think]. And although possibly (or
rather certainly, as I shall say in a moment) I possess a body with which I am very
intimately conjoined, yet because, on the one side, I have a clear and distinct idea of
myself inasmuch as I am only a thinking and unextended thing, and as, on the other, I
possess a distinct idea of body, inasmuch as it is only an extended and unthinking
thing, it is certain that this I [that is to say, my soul by which I am what I am], is entirely
and absolutely distinct from my body, and can exist without it.”
14
7
9/11/14
Some terminology
•  ‘Rigid designator’ is a referring expression that refers to
the very same thing in every possible world in which that
thing exists
–  Examples: proper names, natural kind terms indexicals,
demonstratives
•  ‘Flaccid designator’ is a referring expression that refers to
different things in different possible worlds.
–  Example: definite descriptions
•  More strictly, NI should be stated like this:
•  (NI) Where ‘X’ and ‘Y’ are rigid designators, if ‘X = Y’ is
true, then it is necessarily true -- that is, X = Y in every
possible world.
15
Descartes’ Divisibility Argument in Med 6
“… that there is a great difference between mind and body, inasmuch
as body is by nature always divisible, and the mind is entirely
indivisible. For, as a matter of fact, when I consider the mind, that is to
say, myself inasmuch as I am only a thinking thing, I cannot distinguish
in myself any parts, but apprehend myself to be clearly one and entire;
and although the whole mind seems to be u nited to the whole body,
yet if a foot, or an arm, or some other part, is separated from my body, I
am aware that nothing has been taken away from my mind. And the
faculties of willing, feeling, conceiving, etc. cannot be properly speaking
said to be its parts, for it is one and the same mind which employs itself
in willing and in feeling and understanding. But it is quite otherwise with
corporeal or extended objects, for there is not one of these imaginable
by me which my mind cannot easily divide into parts, and which
consequently I do not recognize as being divisible; this would be
sufficient to teach me that the mind or soul of man is entirely different
from the body, if I had not already learned it from other sources.”
16
8
9/11/14
Descartes’ argument recast
•  1. It is conceivable that M and B are distinct
•  2. So, it’s possible that they are distinct
•  3. So, they are distinct
•  If ‘M’ and ‘B’ are rigid designators, the argument can be
truned into a valid argument.
17
How could two such radically different substances
causally interact?
•  Descartes in Meditation 6:
“The mind is not immediately affected by all parts of the
body, but only by the brain, or perhaps just by one small
part of the brain. . . . Every time this part of the brain is in
a given state, it presents the same signals to the mind,
even though the other parts of the body may be in a
different condition at the time. . . . For example, when the
nerves in the foot are set in motion in a violent and
unusual manner, this motion, by way of the spinal cord,
reaches the inner parts of the brain, and there gives the
mind its signal for having a certain sensation, namely the
sensation of a pain as occurring in the foot. This
stimulates the mind to do its best to get rid of the cause of
the pain, which it takes to be harmful to the foot.”
18
9
9/11/14
Objection by Princess Elisabeth of Bohemia
•  She wrote to him in May 1643, challenging him to explain:
“how the mind of a human being, being only a thinking
substance, can determine the bodily spirits in producing
bodily actions. For it appears that all determination of
movement is produced by the pushing of the thing being
moved, by the manner in which it is pushed by that which
moves it, or else by the qualification and figure of the
surface of the latter. Contact is required for the first two
conditions, and extension for the third. [But] you entirely
exclude the latter from the notion you have of the body,
and the former seems incompatible with an immaterial
thing.”
19
Descartes’ response to Elisabeth
“I observe that there are in us certain primitive notions
which are, as it were the originals on the pattern of which
we form all of other thoughts, . . . As regards the mind and
body together, we have only the primitive notion of their
union, on which depends our notion of the mind's power to
move the body, and the body's power to act on the mind
and cause sensations and passions.”
•  The notion of mind-body union is a primitive notion and
the notion of mind-body causal interaction depends on
and derives from that primitive notion, hence no the
explanatory buck stops there.
20
10
9/11/14
Elisabeth responds:
“And I admit that it would be easier for me to concede
matter and extension to the mind than it would be for me
to concede the capacity to move a body and be moved by
one to an immaterial thing.”
•  Accepting materialism is intellectually less costly than
accepting Cartesian substance dualism, hence
materialism must be preferred!
•  This is a succinct statement of the so-called
Causal Argument for Materialism.
21
The “Pairing Problem” (General)
22
11
9/11/14
Mental-Physical Pairing Problem
(M**)
23
Mind-to-Mind Pairing Problem
Space provides the Principle of Individuation
for matter (material, corporeal, substances)
24
12
9/11/14
Can We Locate Cartesian Minds in Space?
•  This can only be done if the mental substances are geometric
points!
•  Mental substances has no extension (no physical dimensions)
So where to put these points then?
•  In the brain, where?
•  The choice has to be arbitrary when we know that several
different regions in the brain support different mental capacities
•  Suppose we can decide this issue, what keeps the mind glued
to this location?
•  Still is any more intelligible to say that all causal interactions
orchestrated through this point?
•  Can there be many minds in the same geometrical point?
•  If not why not?
25
13