”Cogito ergo sum” is a translation of Descartes’ original French statement: “Je pense, donc je suis”. Philosophers love to translate everything into Latin to make it just a little bit cooler sounding.
(Pronounced: Kog-e-toe, Air-go Sum)
Certainly the most famous sentence in philosophy, Rene Descartes’s ‘cogito, ergo sum - I think, therefore I am - appears in his work Discourse on Method.
Descartes’s famous conclusion came at the end of a self imposed project to subject all of his beliefs to radical doubt and reject any belief that he could not know for certain to be true. (He gave himself one pass since he still believed that his mother loved him even though she named him Rene.)
He rejected his belief in the world of sensory experience because he believed his senses could be deceived knowing for a fact that everything could not possibly taste like chicken. However, he found one belief he could not doubt - that he was thinking. Descartes found it to be impossible to doubt that he was thinking, because in doubting it, he would be thinking. Exactly the same kind of logic that thirteen year olds use on each other to prove that they didn’t do it.
Descartes declared that if he knew for certain that he was thinking, he also knew for certain that he existed. Thus, he had discovered one unquestionable belief - that he existed.
Philosophers have used Descartes as a jumping off point for what is called the Problem of Self-Knowledge: What is unique about our awareness of ourselves from the inside? That is, in what ways is it different to think about our own thoughts, feelings, and desires as opposed to anything else? Again, just like a thirteen year old.
Some people think one difference is that we cannot be mistaken when we honestly report what we are thinking or feeling. Thus, If you feel that you are in pain, it seems impossible that you could be wrong in believing you are in pain. It works equally well for hunger.
Descartes believed that he had provided a proof of the existence of God that was so strong it could not possibly be doubted.
Parodies and pop-cultural references
Blogito, ergo sum, I blog, therefore I am.
Poto, ergo sum: I drink, therefore I am.
In The Adventures of Baron Munchausen the King of the Moon, claiming that he is the creator of everything, says “Cogito ergo es” translating it himself as “I think, therefore you is.” (The actual translation being “I think, therefore you are”.)