Some of Descartes' Arguments for Dualism

As we saw, Descartes is a substance dualist. We're going to spend a lot of time beating up on this view, and offerring alternatives, but it's important to remember that Descartes did have some arguments for his position. He offers many arguments in the Meditations, and also in his Discourse on Method. In class, I described two of the arguments that appear in Meditation II.

A General Principle

Descartes claims that the mind is distinct from (not identical with) anything physical. To try to prove this, he relies on a general principle about identity and distinctness, namely:

Argument from Doubt

In Meditation II, Descartes gives a couple of different arguments that the mind is distinct from the body. The first is what I called the "Argument from Doubt".
1. I can doubt that my body exists.
2. I cannot doubt that my mind exists.

\3. Therefore, my mind is distinct from my body. [from 1 and 2]
Premise 1 is supported by his skeptical arguments, e.g. the Evil Demon argument. Premise 2 is from the "Cogito".
Note: This argument will work if you substitute any physical thing for "my body". Thus, if successful, this argument will show that the mind is not identical to anything physical. (And that's substance dualism!)

The Masked Man Fallacy (?)

One of the oldest and most common objection to Descartes' argument is that is commits what's known as "The Masked Man Fallacy". (I know who my father is. I don't know who that masked man is. Therefore, that masked man is not my father.) Blackburn asks us to compare the argument from doubt with the following argument: (Think, pp. 29-30)
1. I can doubt whether a person who will get bad news tomorrow is in this room.
2. I cannot doubt that I am in this room.

\3. I am not a person who will get bad news tomorrow. [1,2]
This argument has the same form as the argument from doubt, but it is clearly invalid.

The Argument from the Ball of Wax

Now, Descartes was surely well aware of this fallacy (it had been first noticed centuries earlier), so maybe he was just warming us up. In Meditation II he gives a different argument for dualism. This comes out of his discussion of the ball of wax. (As I pointed out in class, Descartes was trying to illustrate a number of things in this discussion. One of his main points was an articulation of his "rationalism". But I think we can tease out an argument for dualism.)
1.My body is not strictly perceived by the senses, but is indirectly understood by the intellect. [Defended by reasoning about the Ball of Wax]
2. My mind is perceived or encountered directly (by me, or itself).
3. If X is directly perceived or encountered by me, while Y is not strictly perceived but only indirectly understood, then "I can achieve an easier and more evident perception of... [X] than of... [Y]."
\4. I can achieve an easier and more evident perception of my mind than of my body. [1,2,3]
5. If I can achieve an easier and more evident perception of X than of Y, then X is distinct from Y. [A specific instance of the "General Principle"]

\ 6. My mind is distinct from my body. [4,5]
(Again, this argument is supposed to work no matter what physical thing you substitute for "my body".)

I leave it as an open question whether this argument is valid:
Has Descartes committed the "Masked Man" or some similar fallacy, or is this argument successful?