[B-Chan]

The Cartesian credo of the current rationalist/materialist religion is "I think, therefore I am."

But how can one demonstrate the fact that one thinks?

They cannot. It is impossible to "prove" that one exists, because it is impossible to "prove" that one thinks. We directly experience our own existence -- but it is impossible to demonstrate that existence scientifically. We all take our own existence on faith.

Therefore, even rationalism is based on unprovable faith.

B-chan

[diotima]

Some have argued, like Hintikka, that cogito ergo sum is "demonstrated" because it is meant to be a performative assertion: the act of its assertion is, via performance, its truth. Along the same lines cogito ergo sum can also be translated as "I am thinking, therefore I am."

I always liked the second meditation the best.

[weikel]

Everything except the existence of your own consciousness( in some form) requires a tiny element of faith. However I can't think of a satisfactory refutation to the pure logic of I think therefore I am.

[The Green Goblin]

But how can one demonstrate the fact that one thinks? They cannot. It is impossible to "prove" that one exists, because it is impossible to "prove" that one thinks.

The fact that one thinks is proof in itself. Your own argument proves you wrong, because the concept of "demonstration" is only applicaple to a thinking entity...