Rene Descartes and his skeptic philosophy part 1: Doubting everything we know.

Descartes is undoubtedly one of the most famous philosophers, so much so that his famous lines cogito ergo sum is engraved into the history of mankind and is known by many, even by the ones not particularly interested in philosophy. Now, let's discover what that famous line of his means, how he tries to find certainty while doubting everything, including his existence, and how he methodologically tries to prove his existence beyond doubt. To achieve this, we will look at his book Meditations on First Philosophy, which is one of the most influential works in the history of philosophy. This book is separated into six meditations, in which he systematically doubts everything he believes to establish a solid philosophical framework that would provide certainty beyond any doubt. In this first part, we will only look at his first two meditations.

First Meditation: Descartes begins by doubting all of his previously held beliefs. For example, he believes that what he sees in front of him is what is really there. However, he observes that our senses can deceive us, and be quite unreliable. Our eyesight, hearing, smelling, and touching; essentially the main organs responsible to deliver information about the world, might provide us with wrong information. We might see objects differently than they really are, or can see things that are not there, etc. Hence, he doubts all of his beliefs that are built upon his senses.

“Whatever I have up till now accepted as most true and assured I have gotten either from the senses or through the senses. But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once.”

How you think are reading this right now might not be the reality. All the beliefs that build your reality are delivered by your senses, which are not reliable at all. This might all be a dream, and since there is no principled way of distinguishing waking life from dreams, any belief based on sensation is doubtful. Or, as he gives another famous example, a devil might be deceiving our senses. Since there is room for any doubt, we can never be certain of the reality of our experiences.

“ I perceive so clearly that there exist no certain marks by which the state of waking can ever be distinguished from sleep, that I feel greatly astonished; and in amazement I almost persuade myself that I am now dreaming.”

Second Meditation: Here, Descartes tries to form a reliable foundation that he can build all his beliefs upon which leaves no room for doubt. He established undoubtable certainty in his famous lines: Cogito, ergo sum, meaning I think, therefore I am.

“And let him do his best at deception, he will never bring it about that I am nothing so long as I shall think that I am something.”

The only fact that I can never doubt is the fact that I am thinking. Even if I am dreaming, or an evil devil is deceiving my senses, there must be an I, a thinking thing. This is where the Cartesian Dualism comes from. I still doubt everything else except the fact that I am a thinking thing, including my belief that I have a body. He separates the mind from the body. Or in a modern sense, material from the mental. In conclusion, he found an absolutely certain belief that other absolutely certain truths can be deduced.

“Mind and soul of the man is entirely different from the body.”

In the first two meditations, Descartes first doubted everything he believed, then found a foundation on which he can build all his other beliefs onto. In the later four meditations, he will use the undoubtable fact that he exists and that he is a thinking thing, to deduce other undoubtable truths, including the reality of our experiences and the existence of God.

The Sources:

https://iep.utm.edu/rene-descartes/