René Descartes once wrote ‘Cogito ergo sum’ which is a Latin philosophical proposition that appeared in his Discourse on the Method, but this phrase was originally written in French as ‘je pense, donc je suis’, because he felt this would reach a wider audience than Latin. Most people are aware that Descartes said, ‘I think therefore I am’, but they actually have no clue what this one-liner means. Only a deep thinker who attempts to find the foundational truths for knowledge would doubt their own existence. Descartes writes his First Meditations where he explains why he can call his beliefs into doubt, since his beliefs have deceived him before and he goes on to argue that perhaps he is currently dreaming or that God is actually a deceiving demon, or that he is simply crazy.
Descartes is a man of reason who is skeptical of all his beliefs, and this leads into his Second Meditations, where he convinces himself that nothing of the world is real. By disbelieving everything, he feels that even our very existence can be thought to be nothing. He convinces himself that he is existing in a world where there is nothing, no sky, no earth, no minds, no bodies and he figures that in this made up world he would also not exist. Then he counters this by thinking that he must exist if it is him that convinced this odd place. He thinks that it is possible that he is being deceived, by someone that is supremely powerful and cunning whose aim is to see that he is always being deceived. However because he is being deceived this must mean that he does exist. He rants, ‘Let him deceive me all he can, he will never make it the case that I am nothing while I think that I am something. Thus having fully weighed every consideration, I must finally conclude that the statement “I am, I exist” must be true whenever I state it or mentally consider it.’
I try to make this simpler for my students by telling them that Descartes was trying to say that he understood that he was alive, because he knew that his brain was still working. I feel that the best way to get my students interested in Math, is to start out by engaging them in a story. I tell them about the famous French philosopher and then I ask them what they think it means, before I go on to explain Cartesian coordinates to them.
My post for Linda G. Hill’s One-Liner Wednesday