I'm meeting today with a student who has asked me the question: "How do we know that persons have souls?"
I'll do my best to explain reasons #s 1 & 2 below.
All this is taken directly from: J. P. Moreland, The Soul: How We Know It's Real and Why It Matters.
At least five arguments have been offered in the recent
literature for some form of substance dualism (i.e., the view that the body and the soul are two different substances).
#1 -
FREE WILL, MORALITY, RESPONSIBILITY, AND PUNISHMENT
Consider the following
argument:
(1) If I
am a physical object (e.g., a brain or a body), then I do not have free will.
(2) But
I do have free will.
(3) Therefore,
I am not a physical object.
(4) I am
either a physical object or a soul.
(5) Therefore, I am a soul.
When I use the term free
will, I mean what is called libertarian freedom. I can literally choose to act
or refrain from acting. No circumstances exist that are sufficient to determine
my choice. My choice is up to me. I act as an agent who is the ultimate
originator of my own actions.
“If physicalism is true,
then human free will does not exist. Instead, determinism is true. If I am
just a physical system, there is nothing in me that has the capacity to freely
choose to do something.” (Moreland, 129)
When it comes to morality,
it is hard to make sense of moral obligation and responsibility if determinism
is true. They seem to presuppose freedom of the will. If I “ought” to do
something, it seems to be necessary to suppose that I can do it, that I could
have done otherwise, and that I am in control of my actions.
It is safe to say that
physicalism requires a radical revision of our commonsense notions of freedom,
moral obligation, responsibility, and punishment. On the other hand, if these
commonsense notions are true, physicalism is false.
#2
- SAMENESS OF THE SELF OVER TIME
Consider the following
argument:
(1) If something is a
physical object composed of parts, it does not survive over time as the same
object if it comes to have different parts.
(2) My body and brain are physical
objects composed of parts.
(3) Therefore, my body and
brain do not survive over time as the same objects if they come to have
different parts.
(4) My body and brain are
constantly coming to have different parts.
(5) Therefore, my body and
brain do not survive over time as the same objects.
(6) I do survive over time
as the same object.
(7) Therefore, I am not my
body or my brain.
(8) I am either a soul or a
body or a brain.
(9) Therefore, I am a soul.
#3 -
OUR BASIC AWARENESS OF THE SELF
Stewart Goetz has advanced the following type of argument
for the nonphysical nature of the self, which I have modified:
(1) I am essentially an indivisible, simple spiritual
substance.
(2) Any physical body is essentially a divisible or
complex entity (any physical body has spatial extension or separable parts).
(3) The law of identity pertains (if x is identical to y,
then whatever is true of x is true of y, and vice versa).
(4) Therefore, I am not identical with my (or any)
physical body.
(5) If I am not identical with a physical body, then I am
a soul.
(6) Therefore, I am a soul.
Premise 1 seems obvious.
Premise 5 is common sense.
Premise 1 is true by introspection. We are just aware of
ourselves as simple, complex things.
Premise 3 – I am not identical to my body or my conscious
states. Rather, I am the immaterial self that has a body and a conscious mental life.
#4 -
UNITY AND THE FIRST-PERSON PERSPECTIVE
Consider the following argument:
(1) If I were a physical object (e.g., a brain or body),
then a third-person physical description would capture all the facts that are
true of me.
(2) But a third-person physical description does not
capture all the facts that are true of me.
(3) Therefore, I am not a physical object.
(4) I am either a physical object or a soul.
(5) Therefore, I am a soul.
A complete physical description of the world would be one
in which everything would be exhaustively described from a third-person point
of view in terms of objects, properties, processes, and their spatiotemporal
locations.
“No amount of third-person descriptions captures my own
subjective, first-person acquaintance of my own self in acts of self-awareness.
In fact, for any third-person description of me, it would always be an open
question as to whether the person described in third-person terms was the same
person as I am. I do not know myself because I know some third-person
description of a set of mental and physical properties that apply to me (“So,
the body is five-feet-eight-inches, 160 pounds, and is thinking about lunch? I
think that’s me.”). Instead I know myself as a self immediately through being
acquainted with my own self in an act of self-awareness. I can express that
self-awareness by using the term I. I refers to my own substantial soul.” Moreland, pp.
122-123)
#5 -
THE MODAL ARGUMENT
The core of the modal argument for the soul is fairly
simple:
I am possibly disembodied (I could survive without my
brain or body).
My brain or body are not possibly disembodied (they could
not survive without being physical).
So I am not my brain or body.
I am either a soul or a brain or a body.
So I am a soul.
Here is an expanded version of this argument.
1. The
law of identity: If x is identical to y, then whatever is true of x is true of
y and vice versa.
2. I
can strongly conceive of myself as existing disembodied. (For example, I have
no difficulty believing that out-of-body near-death experiences are possible;
that is, they could be true.)
3. If I
can strongly conceive of some state of affairs S (e.g., my disembodied
existence) that S possibly obtains, then I have good grounds for believing that
S is possible.
4. Therefore,
I have good grounds for believing of myself that it is possible for me to exist
and be disembodied.
5. If
some entity x (for example, my self) is such that it is possible for x to exist
without y (for example, my brain or body), then (i) x (my self) is not
identical to y (my brain or body) and (ii) y (my brain or body) is not
essential to x (me).
6. My
body (or brain) is not such that it is possible to exist disembodied, i.e., my
body (or brain) is essentially physical.
7. Therefore,
I have good grounds for believing of myself that I am not identical to my body
(or brain) and that my physical body is not essential to me.
