Amy Xu
Seminar II
Paper I
2/26/2014

Different Realities The difference between realities and dreams is whether we choose to believe them or not. The decision of believing or not is made by our minds. People make different decisions, which make people possess different definitions of reality. Descartes and Galileo had their different opinions about reality. I believe everyone has a “standard” of reality in his or her mind. The reality that we choose to believe, we should value, not doubt; the dreams that we choose not to believe are not worth rethinking, we should abandon them. We all live in what we believe is reality. Since we have made the decision, then we should trust it. Descartes and Galileo seem to have noting in common. However, they each had their unique definitions of reality. Descartes's opinion of reality is that the only thing we can trust is our existence. In the book Meditations on First Philosophy, Descartes proposed that he could be dreaming at any moment, or God could be deceiving his senses: “As I consider these matters more carefully, I see so plainly that there are no definitive signs by which to distinguish being awake from being asleep” (Meditations on First Philosophy, 60). This suggests Descartes would not trust his sense of anything. Descartes claimed, “I think, therefore I am, ”. At first, he did not want to believe in what he believed as reality, and he also distrusted decisions that he had made before. Descartes thought that our senses could not be trusted, because they are easily deceived. The only thing Descartes believed he had ever confirmed is his existence. Galileo's conception of reality is totally different from Descartes'. He thought that reality is what we seem and can measure. For Galileo, reality was based on the scientific world. Galileo's observations about the moon were very accurate and careful for that time period, one of poor technology: “First I prepared a tube of lead, at the ends of which I fitted two glass...for they [stars] appeared three times closer and nine times larger than when seen with the naked eye alone” (Astronomical Message, 29). His measured data was precise, and the repetition of his experiment showed the careful he took to demonstrate that reality is based on science. There is no right and wrong between these two opinions. Both philosophies are respected and had huge impacts on human civilization. They both were persuasive and logical and arrived at reasonable opinions. Descartes thought that we could not trust our senses because someone may deceive us and make us believe the wrong things. By contract, Galileo believed reality is based on observations. He used scientific methods to confirm reality: what we see and what we measure is true. Descartes is drawing conclusions from the internal “mind” world, through thinking and meditating. Galileo is gaining evidence through his senses by using a scientific method and technology to come up with a result. In my opinion, Descartes's meditation is less persuasive. I would say that all the conclusions that Descartes reached were based on his identity and experience, that he had learned everything from the past. Identity means who we are, which decides the way we see and understand this world. Our perspective is based on our identity and experience. It is impossible for us to overturn what we know and rebuild our mental worlds. For example, we all know that one plus one equals two. In fact, we use this equation to prove others. However, if we want to use these other equations to prove that one plus one does not equal two, then all the other equations we know no longer make sense because we no longer accept the foundation equation. Descartes cannot use his senses to conclude that he cannot trust his senses. He believes only in his existence, not other things: “I must take steps to keep myself mindful of them. For long-standing opinions keep returning,