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.
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.
i am i exist
Descartes' evil genius argument is a thought experiment in which he doubts everything he knows by considering the possibility of an evil genius deceiving him, creating a scenario where his beliefs about the external world could be false. This skeptical scenario aims to demonstrate the limits of human knowledge and the need for a reliable foundation for beliefs.
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 hopes to find out what he can know for certain, without any doubt, about the world and nature.
"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.
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.
In the Third Meditation, Descartes aims to establish the existence of God through his "Trademark Argument." He argues that the idea of God as a perfect being must have originated from a perfect being and could not have been created by imperfect humans. This leads him to conclude that God exists and is the guarantor of the truth of clear and distinct ideas.
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.