Now that I have learned and studied up a bit more on Rene Descartes and the idea of "I think, therefore I am," I think (see what I did there?) that I am able to understand this simple, but deep quote a bit better. So Rene Descartes based all of his Philosophy on the one idea of "radical doubt," which is the belief to doubt everything and everyone you've ever known until you have sufficient evidence to prove that what you know is true. Rene Descartes was then trying to find which beliefs he had known in all his life that he knew were undoubtly true, otherwise known as irrefutable truths. The only one he could find was thinking because he pondered and pondered, wondering how could this be proven. It struck him that he knows that right now he is thinking, and he can't prove otherwise because he was still thinking. Basically he always knew that he was thinking because of this proof. One other philosophical question Rene Descartes was if we were all truly alive and living in the real world, or if we were simply figements of an imagination, such as a dream. He used the irrefutable truth of thinking to then help him answer this question. His answer was that if he was thinking, he was alive and real because if you weren't pondering your existence, then you wouldn't exist. Once again this is an irrefutable truth because if you doubt your existence, you're still thinking about you existing, which means you exist, if that makes any sense. This statement transformed into the quote we all know, "I think, therefore I am," and helped contribute to lot's of philosophers around the world.