Philosophy

Rene Descartes is called the father of Western Philosophy, but he can more truly be stated to be the founding father of the idealist school of thought which considers human thought to be the source of all understanding and knowledge, even of material things that lie outside its ambit. Descartes, in his Meditations, starts working against the context of the long established Aristotelian philosophy that bases itself on sensory perceptions. It also stands distinct from the metaphysical overtones of some of Aristotles writing that distinguishes between object and its essence, existing simultaneously. Considering all philosophy that comes before him as erroneous, as they are largely understood through senses, Descartes starts to build his new system based on cognition.

Descartes starts his philosophy through a stated distrust of the senses. He asserts that senses could be deceived by God or by the devil, or under the influence of hallucinations or other cloudiness of perception, and thus is never to be trusted. As a result, all knowledge based on sensory perception becomes an object of suspicion for Descartes

I have noticed that the senses are sometimes deceptive and it is a mark of prudence never to place our complete trust in those who have deceived us even once.

He starts therefore by the only thing that he is most sure of  his existence. Existence, for Descartes, is the one entity that cannot be doubted. To doubt it would be a logical fallacy, because the questioning and the doubting of it presuppose its very existence. In other words, it has to exist to doubt it exists. As a result, the only sure thing that one can be sure of is existence. He further concludes that he is sure of this existence because he is thinking. It is only his thought that makes him certain of his existence. Hume reasons further that he comes to think of this fact through his intellect, and that the mind is better known to him than the body.

Descartes further reasons that God cannot be understood by the mind because he is too perfect to be conceived by the intellect. Only a being as perfect as God can understand God, and the only thing he can do is to pray for assistance to guide his enquiry in the right direction. This line of thought leads Descartes to come to the question of existence of God. Any error, Descartes argues, arises not because of God, but because of the human will to pass judgment on things that the mind does not comprehend.

Descartes, through an intelligent thought of cohesion, connects this to his meditations on thought as the parameter of existence. He sees the body as an extension, with the only physical qualities being material quantifications like breadth, length, size, shape, etc. Thus, the primary attribute of the body is extension. Descartes contrasts the essentially extended nature of the body to the essentially existent nature of God. Thus a God that does not exist is as inconceivable as a body that is not extended.

This leads Descartes to create the most important schema of his philosophical enquiry that between material existence that operates through extension, and the faculty of thought. The first principle is the material world and the second principle the mind and the intellect. While an understanding of the first principle is clear and by and large unambiguous, the second he states is obscure and cloudy. The reason, Descartes concludes, is the error of approaching the secondary through the primary, the mind through the senses, and the essential through the extended. Since the mind is the seat of existence, and the mind is separate from the body, and the only truth beyond doubt is existence itself, the senses can never lead to the truth.

Descartes theory of considering the mind as the locus of all knowledge and understanding gives rise to the school of idealism in Western philosophy, which comes in direct contrast with the empiricist school which considers senses to be the only authentic source of knowledge and everything else as the belonging to the realm of doubtful metaphysics. Hume is one of the chief proponents of this view, and stands as a pillar of Western philosophy directly in contrast to Descartes.

Hume begins his Enquiry on a line of laying out the principles of perception, a method very similar as found in Descartes Meditations. He first makes a distinction between impressions and ideas. The former are feelings, emotions, and all other kind of mental phenomenon that we directly experience. The second he says, are the beliefs and memories we have of these sensations. Hume states that all ideas are fundamentally based on simple impressions through the laws of association, resemblance and contiguity and cause and effect. As an example, Hume states that our knowledge of the Sun rising tomorrow is based on our impression that the Sun rises everyday.

Once isolating ideas from impressions, Hume distinguishes between ideas and matters of fact. Ideas, according to Hume, are usually pure and in the form of mathematical truths and are therefore undeniable on a logical basis. Matters of facts, on the other hand, are based on experience. Matters of fact are based on the knowledge of cause and effect  where cause, even unobserved ones, is generally a result of direct impression that cannot be justified. For example, we cannot always predict the future from experiences of the past, except for a dependence on the law of probability. This probability is a result of our experience. If our experiences have found a long standing connection between two events connected through the law of probability, the mind will follow it and make a strong causal connection between them. Thus all events can be reduced to simple impression and the experience based on it. Hume extends this theory to include the laws of free will and predetermination.

Towards the end of the Enquiry, Hume introduces a number of discussions that appear in the way of inferences from his main theoretical formulation. In this part, he discards speculative forms of religious and metaphysical philosophy and undoes the possibility of any kind of belief in the possibility of miracles.

It is interesting that the investigation for the origin of knowledge and the idea of existence brings two philosophers to absolutely opposite conclusions. While Descartes argues for an absolute distrust of the senses and establishes the primacy of thought in the process of understanding the world, Hume goes to the other extreme and argues experience through sensory perceptions. He underpins cognition through a process of impressions and judgment, thus rendering it a finality of stakes as being the source of all knowledge and understanding.