Heusser Philosophy 100 SG #10c

Descartes Dualism

Steps of Early Meditations:

1) The Cogito 2) The Idea of God 3) God is Perfect 4) God Exists

5) God is not a deceiver (Cannot be?) 6) All clear and distinct perceptions are true (God wouldn’t give a faculty which will go wrong so long as I use it correctly).

Descartes’ Proof that the Material World exists:

1) Our ideas of external reality are either caused by the material world, by an evil demon, by God, or by our faculty of imagination.

2) We are not the cause of our ideas (heat, passive visual cues).

3) God is not an evil demon.

4) God is not cause of ideas (possible, but he would not deceive us).

5) Thus, the material world exists as perceived when we use our faculties correctly.

Dualism: If the existence of A can be doubted but B cannot, then A & B must be distinct.

Thus, a human is two things: a space-occupying body and a non-spatial mind (soul).

Med. 6: Proof of Mind/Body Dualism or “Descartes’ Whole Essence is Thinking”:

1) Whatever I clearly and distinctly perceive can exist.

2) Therefore, if I am able to apprehend one thing apart from another clearly and distinctly, it is possible for them to exist separately (1).

3) I have a clear and distinct perception of myself insofar as I am only a thinking and unextended thing, and a clear and distinct idea of body inasmuch as it is only an extended unthinking thing.

4) Therefore, it is possible for the thinking and unextended thing that I am to exist separately from an unthinking and extended thing (2, 3). (So, God can create a mind without a body.)

5) What can be separated from a thing is not part of its essence.

6) Therefore, I am entirely and absolutely distinct from my body and can exist without it (it is not even part of my essence) (4, 5).

A Cartesian Defense of (3):

i) I conceive of body as a complete thing merely by thinking it extended, having figure, etc. and by denying of it everything that belongs to the nature of mind.

ii) I conceive of mind as a complete thing that doubts, wishes, thinks, has pains, etc. although I deny of it anything that pertains to the nature of body.

Another Proof of Dualism:

1) If “A has property P” is intelligible & true, whereas “B has property P” is unintelligible or contradictory, then A and B are different types of things.

2) “Body B is divisible” is intelligible and true, whereas “Mind A is divisible”

is unintelligible or contradictory.

3) So, mind and body are different types of things.

Problems: 1. How do we account for the interaction of mind and body? 2. The Vicious Circle: God’s existence is dubitable unless our reasoning (tools of knowledge) is certain. Our reasoning is dubitable unless God is not an evil deceiver. We do not know this unless we know God exists and is perfect (which is what we are trying to show).