An argument from Peter Geach
Peter Geach (1916-2007)
(“What do we think with? In
God and the Soul, 1994)
Acts of judgment do not stand in ordinary temporal
relations to physical events.
Therefore, acts of judgment are not physical events.
Therefore, the intellectual life of a human being might
continue after death.
Geach’s view of life after death
Continued disembodied thought might have such connection with
the thoughts I have as a living man as to constitute my survival
as a ‘separated soul’. To be sure, such survival must sound a
meagre and unsatisfying thing; particularly if it is the case, as I
should add, that there is no question of sensations and warm
human feelings and mental images existing apart from a living
organism. But I am of the mind of Aquinas about the survival
of ‘separated souls’, when he says in his commentary on I
Corinthians that my soul is not I, and if only my soul is saved
then I am not saved, nor is any man. Even if Christians believe
that there are ‘separated souls’, the Christian hope is the
glorious resurrection of the body, not the survival of a
‘separated soul’(“What Do We Think With?” p. 40).
Descartes and Aquinas: Two views
of mind and body
Descartes
Aquinas
Mind and body are distinct
substances.
All conscious states and
acts are in the mind.
The body is merely a
collection of parts of
matter.
Mind is intellect and will,
which are powers of a
human being.
Acts of intellect and will are
not material processes.
The soul (principle of life)
can exist apart from
matter, but only in an
incomplete and unnatural
state.
Descartes’ two arguments for mindbody dualism
(1) Methodic doubt shows that a human mind does
not have to be extended in order to exist.
On the other hand, a body (material thing) does
not have to include thinking (consciousness) in
order to exist.
Therefore, mind and body are two distinct things.
(2) A human mind is simple; it has no parts.
Every body (material thing) has parts.
Therefore a human mind and a human body are
two distinct things.
Descartes’ First Argument
I ask [my readers] to reflect on their own mind, and all its
attributes. They will find that they cannot be in doubt about
these, even though they suppose that everything they have
ever acquired from their senses is false. They should continue
with this reflection until they have got into the habit of
perceiving the mind clearly and distinctly and of believing that it
can be known more easily than any corporeal thing. . . .
God can bring about whatever we clearly perceive in a way
exactly corresponding to our perception of it. . . . But we clearly
perceive the mind, that is, a thinking substance, apart from the
body, that is, apart from extended substance. And conversely
we can clearly perceive the body apart from the mind (as
everyone readily admits). Therefore the mind can, at least
through the power of God, exist without the body, and similarly
the body can exist without the mind (Second Set of Replies,
CSMK, Vol. 2, p. 115,119).
Descartes’ Second Argument
There is a great difference between the mind and the body,
inasmuch as the body is by its very nature always divisible,
while the mind is utterly indivisible. For when I consider the
mind, or myself in so far as I am merely a thinking thing, I am
unable to distinguish any parts within myself; I understand
myself to be something quite single and complete. Although
the whole mind seems to be united to the whole body, I
recognize that if a foot or arm or any other part o the body is
cut off, nothing has thereby been taken away from the mind . .
. By contrast, there is no corporeal or extended thing that I can
think of which in my thought I cannot easily divide into parts;
and this very fact makes me understand that it is divisible. This
one argument would be enough to show me that the mind is
completely different from the body, even if I did not already
know as much from other considerations (Meditations, CSMK,
Vol. 2, p. 59).
An Objection to Descartes' First Argument
Even if I can be certain that I exist while being in doubt whether I have a given
property, that does not show that I could exist without that property. For
example, even if I can be certain that I exist while being in doubt whether I am
created by God, does not show that I could exist without being created by God.
An Objection to Descartes’ Second Argument
A thing can be divisible in one way and not divisible (simple) in another way. For
example the word ‘if’ is both divisible (into letters) and not divisible (into words).
So even if the mind is not divisible into mental parts, it does not follow that the
mind cannot be divided into material parts.