Wednesday, November 21, 2007

"I Think Therefore I Am" Disproved

Imagine a fictional character with thoughts. It thinks, but it does not exist. So long, basis for Cartesian philosophy. It's that simple. You're done.

Some might object that since our fictional character is imaginary, it doesn't have real thoughts, i.e. doesn't think. However, that alone still disproves Descartes' argument. Why? Well, it turns "I exist" into an implied premise of "I think", and therefore is an example of circular argument (also known as begging the question).

9 Comments:

Blogger FJ said...

The contrapositive of "It thinks, therefore it exists" is "It doesn't exist, therefore it doesn't think." Would you say that is a true statement? Unless I'm remembering this wrong, a statement and it's contrapositive have the same truth value. If the contrapositive is true, so must be the original, "It thinks, therefore it exists."

Where did I go wrong in that argument?

8:22 PM  
Blogger Gideon Humphrey said...

Well, we can either define the word think in such a way that existence is required, or we can define it in such a way that existence isn't required. If we use the former, then Descartes is begging the question. If we use the latter, then a fictional character can think, and serves as a counterexample.

You are doing the contrapositive stuff correctly.

9:26 PM  
Blogger Mike Jewell said...

you said.. "imagine a fictional character thinking"

isn't our act of imagine-ing a fictional character, and making that character exist BY imagine-ing it... isn't that in itself "i think therefore i am"

the fictional character is the "i am"?

8:56 AM  
Blogger Gideon Humphrey said...

That way of defining things isn't very useful since it would mean everything anyone can imagine exists. To put it another way, if I imagine a dragon, does that dragon suddenly exist?

While I could rephrase things in that system, it is more expedient to define existence in such a way that we can imagine things that don't exist.

9:00 AM  
Blogger Mike Jewell said...

This comment has been removed by the author.

8:19 AM  
Blogger Mike Jewell said...

yes... the dragon DOES exist.... somewhere...

"catch me, stan. almost there!" - 'heroin hero dragon'

8:20 AM  
Blogger Gideon Humphrey said...

Fine, but I don't think that kind of existence is what Descartes meant. And if it is, the argument doesn't seem very forceful.

9:36 PM  
Blogger Weles said...

The problem with this is, that we cannot know wether it thinks or not. "I think therefor I am" can only prove my existence to myself. For others it is "I think it thinks" and "I think it exists". There is no it, everything outside my mind can be just ilusion and there is no way to know for certain it isnt. Thats what "I think therefor I am" says.

10:39 AM  
Anonymous Anonymous said...

Your missing the point of the argument. "I think therefore I am" relies on subjectivity. Descartes doubted everything and could not say "you think therefore you are" one can only say with certainty "I think therefore I am."

9:22 AM  

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