René Descartes was a famous French mathematician, scientist, and philosopher. He was arguably known as the "Father of Modern Philosophy." Descartes published many works of mathematics and philosophy throughout his life. In one of his most important works, Meditations on First Philosophy, he added a number of arguments for and against skepticism. Skepticism is the doubt about the truth of something and that absolute knowledge is not possible. Like past famous philosophers before him, Plato and Parmenides, Descartes believed that "evidence from the senses was inadequate to prove the kind of justification required for a claim of knowledge."
In the first of Rene Descartes Meditations, he provided arguments for the skeptical position. He realized that, based off his senses, he had accepted many false opinions as true and that everything he afterwards built upon his opinions could only be doubtful and uncertain. In his project, a quest for knowledge, he decided to disregard and discard all beliefs that were based on any evidence which could be doubted and proven as less than certain. He wanted to create a new, firm foundation. He decided to go about this project because he, like other famous philosophers, believed that much of what is believed is based on ones senses. Descartes noticed that his senses had often deceived him and it was prudent to trust completely in what has deceived a person even once. Aside from deceiving senses, Descartes was also reminded that everyone has dreamed and in one's dream, he or she is not aware that they are dreaming and could simply be dreaming that he or she is sensing. Even if one uses their senses or is dreaming to justify their knowledge, there is no certainty that everything they know is absolutely true. To test this theory, Descartes convinced himself that all he sees and believes he knows is false and non-existent. He persuaded himself that he had no body or senses, and that there was no sky, earth, or minds. Although he doubted all that he believed in, he could not doubt that he exists because he thinks. Besides René Descartes' belief that although one may doubt, one cannot doubt that one exists; one of his most well known philosophical ideas is the method of hyperbolical doubt. The method of hyperbolical doubt, also known as methodic doubt, is a methodical process of being skeptical about the truth of one's belief. According to the article “Descartes’ Epistemology,” Hyperbolical Doubt is perceived to mean that one applies doubt to all candidates of knowledge. However, Descartes sees hyperbolical doubt as this: when one decides to doubt their knowledge, one must apply their doubt to all candidates collectively and start at the foundation. As the phrase goes, "one bad apple can spoil a bunch," one false piece of knowledge can cause an entire belief to collapse. René Descartes describes three skeptical arguments in Meditation I. The first argument is about how one cannot rely solely on senses for knowledge because senses can be deceiving. One often makes decisions and judgments based on what one sees, hears, feels, smells, and so forth; therefore, when one experiences some form of sensory illusion, their judgment is impaired and the information can possibly be false. For example, a person can be driving on a highway on a scorching hot summer day and be absolutely certain that he or she sees a puddle of water on the road ahead. However, the closer they get to the “puddle of water,” they quickly realize that it was an illusion of the sun. Their eyes deceived them and the knowledge which they thought to be true was simply false. The second argument is about being deceived in dreams. In a dream, one experiences senses without actually being aware that one is sensing at all. This raises the question, “are we merely dreaming that we are sensing [in reality]?” The dream doubt challenges the judgment that one is presently awake or is ever awake. Descartes wrote, “every sensory experience I have ever thought I was having while awake I can also think of myself as