Many people have tried to explain and interpret cognition over time. One of the earliest such philosophers was Descartes. He wrote many works on the subject, one of his most famous being the Meditations collection. The collection is also very beneficial to theories today, even though it needs to be refined to fit more modern ideas
In the third meditation, Descartes tries to prove God's existence and that He is not a deceiver, thereby allowing us to be sure that we are not deceived when we perceive things clearly and distinctly. In the rest of the meditations, Descartes tries to prove that he himself is a thinking being and also that the mind is separate from the body.
In Descartes' first meditation, he goes on to prove that nothing exists meaning that because some of our beliefs are based on false pretenses. He establishes that knowledge is built upon a foundation of lesser and simpler ideas that lead to higher levels of understanding.
Each piece of knowledge rests upon some other part of knowledge. Over the course of ones life, a person establishes one piece of knowledge and builds upon that. Descartes goes on to doubt every particular set of knowledge he has.
Descartes says that the most basic set of knowledge we have are our senses. He continues that the senses give us false information. For example, when we look at the sun, we cannot tell how big it is because it is only relative in our field of vision and through a well known phenomenon actually appears smaller and larger during the course of the day pending on its current location relative to the horizon and objects along it. The same is true for dreams. Senses appear to be real in dreams, but can we tell whether or...