common sense believes that there are various reliable sources of knowledge while the skeptic claims there is no secure foundation for knowledge. The two sources of knowledge that he writes about are from the senses and the intellect. Descartes presents the question: are the senses a reliable source of knowledge? This brings us to Descartes argument from Dreaming. In this theory, you compare your dreaming state with your waking state. When we are dreaming, we are not aware that we are dreaming. Things that later strike us as fuzzy, incoherent, far-fetched, or impossible, don’t seem so far within the dream. So that brings up the question: how can we be certain that the experiences we have now are reliable? However, it is worth noting that this is not Descartes own position. His own position is stated in the 6th meditation where he suggests that there are marks present in one’s waking experience in which we can distinguish waking from sleeping. The dream images we imagine are drawn from waking experience. For example, like painting, when a painter creates an imaginary creature like a minotaur, he or she will get the parts of the minotaur from things in real life: horse and man. The painter can doubt composite things, things that are made up together, but cannot doubt the simple and universal parts from which they are constructed. This can be quantity, size, etc. We can doubt studies that are based on composite things, such as medicine, astronomy, or physics, but subjects like arithmetic and geometry are undoubtable.

In Meditation One, Descartes believes that there is indeed a God, someone who is as he says, “all-powerful.” Descartes states, “Perhaps, indeed, there might be some people who would prefer to deny the existence of any God so powerful, rather than believing that all other things are uncertain.” In other words, there are possibly other people who would deny that there is a God than to believe that everything else in the world does not exist. Descartes believes that God?

is being and all other things are not being. All other things in the world compared to God are subordinate because God is almighty.
Another one of Descartes’ theories in Meditation One is the Evil Demon Argument. It is also worth noting that is this not Descartes own position, but uses it as an argumentative device. The Evil Demon Argument states that an evil demon has the will, power, and the knowledge to make a person a constant victim of deception. Even one is thinking something is self-evidently true, it’s not.

There is a distinction between the mind and the body. The mind is essentially thinking and the body is essentially extended so that the two have nothing in common. In Descartes’ Meditations on Philosophy