Hi Jim
As prof. quoted in our 2nd med. notes, descartes wrote "en cogito ergo sum". I have also been told that the translation should read more like "during cognition I must exist". Kinda the same thing to me as "I think therefore I am". The second sounding more poetic. In the second meditation paragraph 6, descartes concludes that he is a thinking thing. Maybe prof. can shed some more light!