i am i exist
Short answer: Descartes' doubt was like WWI - the doubt to end all doubt. Only by doubting everything could Descartes hope to find anything that was certain (even if the only certainty is that nothing else is certain!).
That he is sentient ie that he thinks.
Descartes did not invent polynomials.
Rene Descartes was a French mathematician who created coordinated geometry.
Descartes argued that the mind and body are fundamentally different substances because they possess different essential properties. The mind is immaterial, thinking, and indivisible, while the body is material, extended, and divisible. Therefore, he concluded they cannot be parts of the same entity due to their inherent differences.
René Descartes introduced the concept of the evil genius in his philosophical work to highlight radical skepticism. The evil genius is a hypothetical being that deceives our senses and understanding of reality, leading Descartes to doubt all knowledge acquired through the senses. This doubt serves as the foundation for Descartes' "Cogito, ergo sum" ("I think, therefore I am") argument as a starting point for building his system of knowledge.
Descartes cannot doubt his own existence, as captured in his famous statement "Cogito, ergo sum" - "I think, therefore I am."
i am i exist
Descartes hopes to find out what he can know for certain, without any doubt, about the world and nature.
Short answer: Descartes' doubt was like WWI - the doubt to end all doubt. Only by doubting everything could Descartes hope to find anything that was certain (even if the only certainty is that nothing else is certain!).
That he is sentient ie that he thinks.
Not sure what a "certain" plane is. The Cartesian plane was invented by Rene Descartes.
"I think, therefore I am" is the first truth of which Descartes is certain. This statement, known as cogito ergo sum, demonstrates Descartes' method of doubt by acknowledging that even if all his perceptions are false, his ability to doubt and think proves his existence as a thinking being.
Descartes argues that even if we are dreaming, our ability to think and reason proves our existence. He famously stated "Cogito, ergo sum" ("I think, therefore I am") to demonstrate that even if we doubt everything else, we cannot doubt our own existence as thinking beings.
Descartes believed that the truth must be indubitable because doubting leads to answers. The only thing he perceived to be certain was his own existence.
He can not doubt that he thinks, therefore he exists.