I spell, therefore I am

I'm now reading Descartes in my philosophy class and am having trouble finding my feet, so I sent the following in an email to a few of the other students in the class, in the probably futile hope that I could get them to talk philosophy with me:

Let's say that Descartes is a friend of ours, and he has asked for our help. He says that crucial beliefs of his (e.g., that the earth is still and that the sun travels around it, that material objects just naturally fall downward) have turned out to be false, and he's decided therefore not to trust any of his beliefs, but rather to start over, to doubt everything he can possibly doubt, to challenge every one of his preconceptions, his hope being that what is left standing will provide a foundation for all of his succeeding inquiries. The help he is requesting is that each of us do the same: doubt everything we can, and bring him the results.

( I spell, therefore I am )