"Cogito Ergo Sum" : Latin for "I Think Therefor I Am" by Rene Descartes.
Descartes was a French existentialist philosopher who said that we can prove our existence (if for no other reason) than by the fact that we are actually thinking about or existence -- therefore we must exist.
However, I wonder what various modern day humans would say as proof of their existence?
Modern Teen-age girl: I tweet -- therefor I am.
Miley Cyrus: I twerk -- therefore I am.
Angelina Jolie: I adopt -- therefore I am.
Will Muschamp (Fl. football coach): I always run up the middle on first down -- therefore I am.
Lawyer: I have no scruples -- therefore I am.
Stock Broker: I am greedy -- therefore I am.
Banker: I love money -- therefore I am.
Pot Smoker: HuH?