Rene Descartes was one of the most influential thinkers and philosophers ever. His fascination with the brain and its inner workers was instrumental in his meditations. His knowledge of its functions and abilities was vast by even todayÃÂs standards. Upon doubting the existence of everything he could not prove to be true, he came across one of his more famous theories, that somehow, the brain and the mind were two very separate things.
For something to be essential, or to be the essence of something, it has to be something that without which something could exist, it cannot change. For example, the couch I am sitting on is extended, I could do any number of things to this couch, but it does not remove it from existence and make it immaterial, therefore this couch is essentially extended.
Descartes said that the body is essentially extended, it exists in a three dimensional world.
He can interact with other material things and his faculties sense the presence and qualities of these objects. Descartes said that our bodies were extended and that he could feel pain and pleasure through his senses, but he could not understand whythese physical sensations caused him to react emotionally, or why when his throat was dry he instinctively knew to get a drink. There is no sense that tells us what to do when we feel these things; our senses merely perceive the stimuli, not react to them1. He also states that although the body is made of many different parts, it is thought to be one whole, and similarly the mind. However, parts of the body may be removed, but types of thought cannot be removed from the mind. And removal of parts of the body does not affect the abilities of the mind, although other parts...