Skepticism According to Merriam-Webster’s online dictionary, skepticism can be defined, as the doctrine that true knowledge or knowledge in a particular area is uncertain. While numerous philosophers have discussed skepticism in detail over the course of time, perhaps no argument is more popular than that of Rene Descartes. Descartes, a French Philosopher of the 16th and 17th centuries, revolutionized the idea in his 1641 doctrine Meditations on First Philosophy by forcing himself to believe that everything he knew to be true, such as his morals and beliefs. While an obscure thought, he attempted to create a unique set of beliefs that were entirely true, and explained such in Meditation 1 when he said, “Several years have now elapsed since I first became aware that I had accepted, even from my youth, many false opinions for true, and that consequently what I afterward based on such principles was highly doubtful; and from that time I was convinced of the necessity of undertaking once in my life to rid myself of all the opinions I had adopted, and of commencing anew the work of building from the foundation.” In this quote, Descartes explains how he was led to believe things are true, for example the popular moral that a child can be anything he or she wanted, and sought to fix his belief system to the core. By taking on such a task, he created numerous ideals for skepticism. One of the first ideals of Descartes writings is that we can question reality because one can no decipher dreams from reality. That is to say, there is no specific way to tell when someone is dreaming, or when he or she are awake. Cleverly, this allows for his methods to truly shake his belief foundation. How can one see truth when the reality may, in fact, not actually be reality? While there are numerous ways to quantify it, such as pain receptors or things now known by science that differentiate dreams from reality, Descartes believed that the world could fool us into believing it, essentially a mirage or hallucination. Under this idea, which he later retracts due to the use of time to differ reality from dream, he sets up the second parallel for his argument. As previously mentioned, the second idea is an extension of a reality based skeptic ideal. In this, Descartes describes a malicious demon that creates a world-like atmosphere. The idea predicates that the demon controls one’s life through deceit and power, and that as a result, all of your senses and beliefs were simply lies fed to you. Essentially, the idea is similar to that of a brain in a vat. Do you exist to create your own knowledge, or do others create knowledge with falsity and deceit in mind? The second was argued by the malicious demon. To combat both of these, the Descartes used the mantra ‘Cogito ergo sum,’ Latin for I Think, I Am. By doing so, Descartes concedes the skepticism can be proven wrong, and that a malicious demon does not create an alternate reality in which all your opinions of knowledge are lies. Argued by the idea that because he thinks he must be real, Descartes determined that because he could not doubt if he actually did not exist.