The passage entitled, Meditations on First Philosophy, by Rene Descartes is a very interesting argument because it challenges any skeptic's idea that nothing exists. This section states that human beings can persuade themselves to believe certain ideas that they believe to be true, or that exist. Descartes questions this existence, as well as its purpose and wonders if someone else could deceive one's self to think these ideas are correct. If a deceiver can change one's thoughts, than this deceiver can never get someone to think that he or she is nothing as long as he or she believes that they are something. In conclusion, Descartes has found a way to prove that everyone believes they exist.
One can be persuaded to believe that something is true if they are given proof and evidence that it is proven to be true. He believes that one's senses do this and cause them to become deceptive of what is true and what is not true. Through the use of different reasoning methods, one can come closer to understanding what the truth really happens to be. If someone really wants to believe that there is not a god, one can do this by finding reasons and sound evidence that proves no gods exist. Even Descartes said, "I have persuaded myself that there is nothing at all in the world" (97). He does believe that he exists though. Descartes has decided for himself that a God does exist, but also leaves open the opinion of others that a God may not exist. He understands why others may not feel there is a God because he cannot prove it or disprove it. This shows that someone can be wrongly persuaded.
If someone can be wrongly persuaded, than that person or thing that is persuading him or her is a deceiver. It is quite possible that everything one believes is false and he or she is being tricked into everything he or she believes. Descartes says, "But perhaps God has not willed that I be thus deceived, for it is said that he is supremely good" (96). This statement would apply if one could prove that God really exists. Is it not possible that "God" is an idea, in which people have been deceived into believing? If "God" is just an idea, then there must be someone or something that deceives people into believing untrue ideas. Later in this passage, Descartes says, "But there is a deceiver (I know not who he is) powerful and sly in the highest degree, who is always purposely deceiving me. Then there is no doubt that I exist, if he deceives me" (97-98). If this case is true, than one cannot be deceived into believing that he or she does not exist as long as one believes he or she does exist. If someone or something is deceiving someone, than that person must exist because there is something that is being deceived. In other words, if someone is being deceived, they must therefore exist.
According to Descartes, knowing that one exists can be proved. If one can think about something, than one must exist. When someone can be persuaded about something either truthfully of falsely, that person does exist because he or she is the thing that something or someone is persuading. Even if one believes everything is false, than one can never be persuaded to think he or she does not exist because he or she is thinking, and therefore, is the subject of a deceiver. Since this is the case, one can exist as long as one believes he or she exists. In this argument, Descartes has shown that people can and must exist even if they are being deceived. The statement Descartes makes, "I am, I exist" (98) is definitely true and one can never be deceived otherwise. In other words, individuals exist and it cannot be proved otherwise.
Descartes has proved his argument to be valid and sound because everyone believes they exist. His argument is valid because everyone really does exist. His argument is sound because the steps lead logically from the premises to the conclusion and is acceptable. Descartes has also proved it to be true that everyone can be persuaded to believe someone or something.