Explain fully “Cognito ergo sum” argument.?

Answer 1

http://en.wikipedia.org/wiki/Ren%C3%A9_Descartes


I think, therefore I am. Cognito, ergo sum. As far as I'm concerned: non sequitar.

Answer 2

_Cogito_ ergo sum ;). Otherwise it sounds like "I'm hidden therefore I am," you know, like incognito?

Anyway, it means "I think, therefore I am." Descartes was a French philosopher and mathematician. He wanted to be able to know what basic principles could be proven absolutely, with the same rigor as the proofs of Mathematics.

He started asking himself, what do I really know for sure? I know I am in France ... but I may be misinformed - I need to take it on other people's word. Okay, I'm a Frenchman ... wait, that is open to doubt to. I am a man! Well, how do I know I'm a man ... my senses after all can deceive me - they have in the past. Maybe I'm only dreaming everything and I'll wake up soon and be someone completely different. Hmm ... well I know one thing for sure - I exist! How do I know I exist? Well, obviously because I'm thinking and pondering about all these things. That must be it! I can know I exist because I am thinking. "Cogito, ergo sum!" Now that I have an absolutely proven first principle, I can build a mathematically sound philosophy ...

The problem of this approach is that the philosopher becomes locked up in his own mind, and cannot make the bridge back to an external, objective reality from the internal, subjective point of view of the individual. It introduces the material/immaterial dichotomy, and seems to paint a picture of man being composed of two halves - one physical, the other spiritual with no connection between them. Descartes is I think the father of modern philosophy, and his seemingly innocent point of departure has caused serious repercussions in modern philosophic development (which is one reason why so many implications of certain modern philosophies seem to smack contrary to normal everyday experience).

Descartes philosophy is significantly different from Ancient Philosophy, which starts with the first principle that reality exists to begin with, which is why we think in the first place. From this perspective one would rather say "Sum, ergo cogito." Existence doesn't depend upon my thinking, my thinking depends upon existence. To a certain extent, this statement requires a certain amount of faith, but this is a faith that is founded in experience, which is just a valid form of knowledge as is a logical proof. You need both, at least if you want to stay sane and consistent :).

Answer 3

What can I know for certain?
I will not believe anything if I can doubt it. My senses may deceive me; there may be no soil, no sky, no living creatures around me.
I am now thinking.
This proves that I exist; I can't doubt that I exist, at least as long as I am thinking.
That's as much as I know of it, but I know that it leads to accepting math and science as valid because they can be proved clearly.