Philosophically, Descartes was concerned with the existence of reality.
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.
Descartes' dream hypothesis suggests that we cannot be certain if we are awake or dreaming, as our senses can deceive us. This challenges our understanding of reality by questioning the reliability of our perceptions and the distinction between what is real and what is imagined.
Descartes creates the evil genius in an attempt to throw everything that he thinks he knows into question. The evil genius has god-like power that he uses to deceive Descartes. Descartes cannot disprove the existence of such a creature. You cannot trust your thoughts in such a scenario, thus Descartes cannot be certain that any of the information he gets from his senses, his memories, his thoughts, or his beliefs is real.
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' dream argument is based on the premise that we cannot trust our senses to accurately perceive reality because we can never be certain if we are awake or dreaming. This uncertainty raises doubts about the reliability of our perceptions and the existence of an external world.
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' philosophy on reality actually shows that we cannot for sure know that we aren' dreaming. In fact, Descartes believed that we are not sure of anything, except for the fact that we exist because we use logic and reason. Sorry that this doesn't answer your question, but the point of this ideology is for others to try to show Descartes how we know FOR CERTAIN that we are not dreaming right now....harder to do than one would think.