cannot be relied on. Descartes then applies the idea of distorted senses to a more common application of dreams. In dreams, the dreamer cannot be sure of whether or not he is dreaming. Although he may try to test his senses, such as touch or movement or vividness, Descartes claims that he has done similar tests while he was actually dreaming. It is possible that a dreamer can have his senses experience the exact same feelings as if he were in the real world, while he was dreaming. Descartes concludes that it is difficult to use one's senses to realize whether or not one is dreaming. Since Descartes cannot prove that we are not dreaming, he makes the assumption that he is in fact dreaming, and that he may or may not have the body he sees. He points out that although he cannot tell whether the images he sees actually exist; they have basic properties in common that must exist in reality. He uses the example of a painter who paints a portrait of a centaur, a mythical beast which is a combination of a horse and a man. Even though the centaur does not exist in reality, he has properties of objects that do exist, namely a man and a horse. Even though he may be dreaming, all of his ideas contain core properties, such as color and quantity, which must be real. Because these core properties deal with simple and abstract ideas, they can be combined to form more complicated and new ideas. Also, because they are general, they do not become false under any amount of scrutiny. He therefore concludes that no matter how much our imaginations and senses toy with our conception of reality, they will always be rooted in some truth. In order to prove that we are not dreaming, Descartes uses the indirect method of reductio ad absurdum.
Since he cannot directly prove that we are not dreaming, he assumes the opposite is true, that we are indeed dreaming. It is assumed that if we were dreaming, then we were imagining all of the events and experiences. That would imply that we do not know anything to be real. However, he shows that there are some concepts that are real, such as arithmetic and geometry, which hold to be true regardless of any object's existence. Since he proves that there is some truth in all that we imagine or dream about, hence the idea that we are dreaming is false. Using this reasoning, he concludes that we are not
dreaming. Descartes' "dream" argument does not give me any inclination to believe that we are indeed awake. In his argument is unsound because he claims that if we were dreaming, then our dreams would be rooted in reality. As said before, Descartes claims that since we know certain truths, such as mathematics, we cannot be dreaming. However, even though we may know mathematics and similar truths, dreams are not defined as being completely unreal and false. In order to make Descartes' argument sound, we would have to accept that dreams have no truth to them. However, dreams can be true or false. Dreams could be true in that something that was a figment of my imagination actually turned out to exist in the real world. For example, when I was young, I dreamed of a combination of a bear and candy. I wasn't until much later that I found out that there was such a thing. It was by pure chance that I dreamt of something and it actually existing in the real world. I agree with Descartes' reasoning using the pyramid. It is true that if you can break the foundation, then the blocks on top of it will crumble as well. However, it is not true that if the foundation was true, that the blocks on top of it were true also. In Descartes' example of the completely new painting, containing the basic principle of color does not mean that it is any more real than if it had no color at all. Having more "transparent truths" does not add to an object's reality. Using the pyramid, the new painting would be on a level above the foundation, the color. The painting must possess something beyond that of color, a mixture of other primary elements, to create something new. This new object can no longer be related to the concept of color, even though it may possess color. Therefore, it is not necessary for the new painting to exist in reality, but it may in fact exist due to chance. However, relying on chance to intricately bring together color and geometry is highly unlikely due to probability. Although it is not ruled out, it is highly unlikely that the object created in the imagination will exist in reality. This means that, using Descartes' idea of basic truths, it is more likely that we are actually awake rather than dreaming. Because it is highly unlikely that all of our present perspectives are due to random mixtures of basic truths, it is more likely that we are living in reality, rather than dreaming up all of our experiences thus far. Descartes' has already proposed another doubt onto this idea using the theory of an evil demon. In the same meditation, he acknowledges the fact that all of our experiences can be due to random chance, and he proposes that an evil demon will cast further doubt as to whether or not we are dreaming. The evil demon suggestion completely eliminates the idea of probability causing our experiences. Now, our experiences would be intentional, deliberately caused by the demon.