Descartes' Method of Doubt - Essay Example

Also in the introductory remarks, Descartes very clearly explains why he believes that leveling all of his beliefs and starting over is the only way to cure science from false and uncertain beliefs. Reason now leads me to think that I should hold back my assent from opinions which are not completely certain and indubitable just as carefully as I do from those which are patently false. So, for the purpose of rejecting all my opinions, it will be enough if I find in each of them at least some reason for doubt (Descartes, 12).

He does not want to simply eliminate the beliefs that he knows for certain are false. He wishes to find indubitable knowledge, and the only way to accomplish this is to reject every belief he possibly can--from the obviously false beliefs to the beliefs that have only the most remote and improbable reason for doubt. Descartes then advances to the first category of beliefs he wishes to cast doubt on--beliefs gained from the senses. Descartes points out that most of the beliefs he is most certain of come from the senses, but that he has noticed that the senses sometimes are deceiving, such as “with respect to objects which are very small or in the distance” (Descartes, 13). . Descartes does come up with a reason you could doubt this belief though, by proposing a new scenario.

The scenario imagines is one where you are caught in a dream. Everyone has had the experience of being in a dream and thinking it is real until waking up, regardless of how fantastical the dream might be. Descartes admits it could certainly be possible that the arms and body he sees do not belong to him, but are part of a dream (Descartes 13). However, he points out that its doubtful that things like arms and hands do not exist altogether, because ideas in dreams are often based on what has been seen in real life.

Even if these body parts were made up though, there are certain beliefs that still cannot be doubted, such as the existence of colors, and the fact that all bodies are extended (Descartes, 14). He points out that even more certain while dreaming are truths derived from mathematics, “for whether I am awake or asleep, two and three added together are five, and a square has no more than four sides” (Descartes, 14). This realization that the most certain empirical truths are merely the existence of bodies and colors, while truths gained through reason such as mathematical truths, leads Descartes to conclude that truths in the sciences are less certain than truths in Mathematics.

Descartes then moves to his final level of doubt, by coming up with the most remote and unlikely, but most powerful scenario yet. He asks us to suppose that there is an evil genius that is infinitely powerful and intelligent, who wishes to trick us into thinking even the most certain things are true. Descartes admits that if such a being exists, even the basic truth that two plus three equals five can be called into doubt. This forces him to come up with his final, most essential