Cartesian Dualism II: A Few Arguments Against CD
 

The Problem of Individuation (Armstrong, 81-83)
 
1. If CD is true, then there are minds.
2. If there are minds, then it is possible to individuate minds.
3. It is not possible to individuate minds.
4. Therefore, it is not the case that CD is true. [1,2,3 MMT]

Here's the extra-credit possibility: Explain and Evaluate Armstrong's "Problem of Individuation" Argument against CD. To explain an argument is to do two things: it is (i) to define all the technical terms in the argument, and (ii) to provide a rationale for each premise. A rationale for a premise is an example, reason, or sub-argument that illustrates why a defender of the argument might believe the premise to be true. You must go line by line when providing rationales for the premises. The rationale for premise (1) is fairly easy to construct. Constructing rationales for premises (2) and (3) is tricky business. Look to the text for quotes that might play a role in these rationales. And don't forget to explain what it means to individuate minds. Bonus points might be awarded to submitters who present an objection to one of these premises on the behalf of the Cartesian Dualist.

 
The Problem of Other Minds (Ryle, 77)
 
1. If CD is true, then it is impossible to tell whether there are any other people.
2. It's not impossible to tell whether there are any other people.
3. Therefore, it's not the case that CD is true. [1,2 MT]

• Be able to provide a rationale for each of these premises.
• Be able to present an objection against one of these premises on the Cartesian Dualist's behalf.
• Be able to evaluate the objection. Will the Typical Materialist be moved by the objection? Why or why not?

From Descartes' Discourse on Method:

"On the other hand, if there were machines which bore a resembalance to our body and imitated our actions as far as it was morally possible to do so, we should always have two very certain tests by which to recognise that, for all that, they were not real men. The first is, that they could never use speech or other signs as we do when placing our thoughts on record for the benefit of others. For we can easily understand a machine's being constituted so that it can utter words, and even emit some responses to action on it of a corporeal kind, which brings about a change in its organs; for instance, if it is touched in a particular part it may ask what we wish to say to it; if in another part it may exclaim that it is being hurt, and so on. But it never happens that it arranges its speech in various ways, in order to reply appropriately to everything that may be said in its presence, as even the lowest type of man can do."

From the Stanford Encyclopedia of Philosophy:

Turing (1950) describes the following kind of game. Suppose that we have a person, a machine, and an interrogator. The interrogator is in a room separated from the other person and the machine. The object of the game is for the interrogator to determine which of the other two is the person, and which is the machine. The interrogator knows the other person and the machine by the labels ‘X’ and ‘Y’ -- but, at least at the beginning of the game, does not know which of the other person and the machine is ‘X’ -- and at the end of the game says either ‘X is the person and Y is the machine’ or ‘X is the machine and Y is the person’. The interrogator is allowed to put questions to the person and the machine of the following kind: “Will X please tell me whether X plays chess?” Whichever of the machine and the other person is X must answer questions that are addressed to X. The object of the machine is to try to cause the interrogator to mistakenly conclude that the machine is the other person; the object of the other person is to try to help the interrogator to correctly identify the machine. About this game, Turing (1950) says:

I believe that in about fifty years' time it will be possible to programme computers, with a storage capacity of about 109, to make them play the imitation game so well that an average interrogator will not have more than 70 percent chance of making the right identification after five minutes of questioning. … I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.

 
The Argument from Causal Interaction (Armstrong, 84-87) (U?, 148-9)
 
1. Mind-body causal interaction is inconceivable.
2. If (1), then mind-body interaction does not occur.
3. If mind-body interaction does not occur, then CD is false.
4. Therefore, CD is false. [1,2,3 MMP]

• Be able to provide a rationale for each of these premises.
• Be able to present an evaluation of the argument.
• Can you single out a problematic premise in this argument? How might a Cartesian Dualist (or any kind of dualist) respond to this argument?