René Descartes

The feedback on the last post relating to David Hume was so positive that I decided to continue summaries of the works of philosophers, in particular one that was mentioned last month and that I have had requests to do in more detail, so without further ado here is Descartes.

René Descartes was a 17^th century French philosopher who is credited with the Cartesian line graph, indices and the law of conservation of mechanical momentum. However throughout his life Descartes battled with with epistemological nihilism, which lead to his own principle of methodological scepticism, essentially Descartes disregarded everything that he thought he knew and tried to think about what he could categorically state that he knew. Descartes came to the startling realisation that there was basically nothing that could be said to be true, as all knowledge we have comes from the senses which are fundamentally fallible, therefore everything we believe we know actually requires a varying level of belief. However Descartes concluded that even if nothing he observed was real, he himself must be in some sense real as he was asking the questions about what is real. This he summed up with “I think therefore I am.”

Descartes progressively added more to the index of knowledge with mathematical axioms such as a square, Descartes concluded that no matter how deluded someone was it is impossible to deny that a shape with four sides of equal length and four angles of the same degree exists and that thing we call a square, he used this idea of basic principle to argue the existence of God. He stated that the definition of a square necessitated its existence, the same can be said of God. He proposed that existence is a perfection: it would be more perfect to exist than not to exist. Thus, if the notion of God did not include existence, it would not be supremely perfect, as it would be lacking a perfection. Consequently, the notion of a supremely perfect God to not exist is simple incomprehensible. Therefore, according to his nature, God must exist. This is known as the ontological argument for the existence of God. Hume and Kant are both strongly opposed to this idea, Hume disagrees with the principle as it lacks empirical ground and that nothing can exist with any necessity. Kant's criticism is based on the idea of characteristics within the argument, Kant stated “Existence is not a predicate” and thus could not be the starting point of an argument to prove God as it adds nothing to the essence of a being.

“I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.” - René Descartes.