Descartes’ Knowledge Skepticism and Its Criticism
People can form diffident kinds of belief in their knowledge. We know the thing that happening in our surrounding, the thing happened in the past. We also have some scientific of mathematic knowledge. That knowledge is most having strong reasons or evidences for us to believe it is true. However, there are some way to prove that can be doubtable.
For example, I am now standing in front of a door. I can feel, see, touch or even smell it vividly. It seems that we can find a lot of reason to believe there is a door in front of me. But at the same time, I can also find some reason to say it is not. Suppose I am hallucinating or dreaming, then I would not know the door is here. Actually, we cannot provide reason to say then we are having hallucination or not. Therefore, the supporters of skepticism will have an argument like:
P1: If I do not know I am dreaming or not, then I do not know there is a door
P2: I do not know I am dreaming or not
C: Therefore, I do not know there is a door
‘Dreaming’ in the above argument is a skeptical scenario. And ‘there is a door’ can be any knowledge come from external world. Skeptic use this form to prove that we cannot believe any knowledge.
According to Robert Audi, there are two competing epistemic ideals, which is believing the truth and avoiding falsehood. These two ideals are very important for us to form a knowledge or believe. Yet, they will pull against each other.
If we pushed by the former ideal, then it will lead us to credulity, which mean if it seems to a subject is present, then probably it is present. Then we will easily believe something. In the other hand, if we want to avoiding the falsehood, it will lead us to skepticism. Thus, we will believe too little because we only believe on absolute concussive grounds. The later ideal can obviously see in Descartes’ theory.
Descartes found that people always have some wrong knowledge, or they will have some thought which is contradict with each other. He thinks that it is because there is some wrong information in our knowledge and it is difficult for us to identify the true and false knowledge. Therefore, Descartes pointed out that we should doubt all knowledge that we cannot sure that is true. For forming a true believe, we need to find out a basic believe that we cannot doubt. Therefore, we can consider Descartes’ theory is aim at avoiding falsehood. In other words, Descartes was using ‘doubt’ as a method to form a true knowledge.
Besides, the perceptual knowledge we mentioned above, Descartes also thinks it is possible that mathematic knowledge or logic can also be wrong. Assume there is a demon will occur in our mind when we are thinking and it will lie to us, thus there almost everything in our mind is not doubtable. However, there are one thing that we cannot be doubt event every knowledge in our mind can be false, it is ‘I am doubting’ or ‘there is a thinking think doubting something’. Therefore, during the time that we are doubting, there is one thing that we cannot be doubt is doubt itself. It also shows that there are thinking substance is existing. That is also the reason of ‘Cogito ergo sum’ in Descartes’ philosophy.
Therefore, Descartes got a basic belief which cannot be doubt, then he thought we can develop our knowledge base on it. Thus, we can rebuild our knowledge system, and there is no longer any wrong knowledge in our mind. According to this thinking model, Descartes form a traditional foundationalism. Foundationalism believe that one belief will justified by another belief, the relationship of all beliefs in our mind is similar with a building. The foundation of the building is the basic beliefs that do not need to support by other beliefs, which mean the that is self-justified. Thus, truth can be obtained by developing from our basic beliefs. In this case, errors are avoided in the sense that our basic beliefs must be true so what developed above them should not be false.
Descartes make an epistemological turn in whole western philosophy history by creating his skepticism. Philosophers started to think more about epistemology rather metaphysic since 1600. However, even Descartes tried his best to find out the method of forming true knowledge, some knowledge are still wrong even we start from the basic belief of Descartes. It shows that there are some problems in Descartes’ theory. In the after part of this paper, we would like to discuss the potential problems or criticisms of Descartes’ epistemological view.
Firstly, Descartes recognize that there are some notions under ‘I think therefore I exist’ in his ‘Principles of Philosophy’. He said,
‘When I said that the proposition “I think therefore I exist” is the first and most certain thing to occur to anyone who philosophizes in an orderly way, I wasn’t meaning to deny that one must first know what thought, existence and certainty are, and know that it’s impossible for something to think while it doesn’t exist, and the like. But these are utterly simple notions, which don’t on their own give us knowledge of anything that exists; so I didn’t think they needed to be listed.’
According to the quotation above, the reason of ignore those simpler notions is they do not prove any ‘knowledge of anything that exists’. That show the first principle in Descartes’ mind should also contain ‘the knowledge of something existence’. ‘I think therefore I exist’ contain the existence of ‘I’ therefore, it is the first principle but not other. It is making sense theoretically, but this idea actually a bit far away from foundationalism.
if ‘I think therefore I am’ is the only basic belief, then there should not have anything is more basic than it. However, it contains few simpler concept inside, such as ‘think’, ‘I’ or ‘I think therefore I exist’ is the only basic belief which is not doubtable in Descartes’ theory. As a first principle, there should not have any concept which is simpler than it. It is because if there are some beliefs is more fundamental, that is mean that principle need to be justified by others but not self-justified. However, we have to at least understand the concept of thinking and existence to form ‘I think therefore I exist’. Therefore, we cannot say this is a good foundation of knowledge in foundationalism.
Besides, as we mentioned, the aim of the first principle is to prove that ‘I exist’. is shows that ‘I think therefore I exist’ is a deductive knowledge. Yet, we need to have at least one more promise for proving ‘I exist’ by ‘I think’, which is ‘anything can think is exist’. Otherwise, it cannot be a sound argument. Yet, this argument will occur two problems.
First, no matter we are talking about skeptical scenario or Descartes’ theory, we also assume that ‘thinking’ need to have a subject behind. It is because in our language, there must have a subject before ‘think’, ‘think’ as a verb cannot form a meaningful sentence. However, we can imagine thinking itself exist independently. People always presuppose that thinking is showing that something are thinking, but they do not a certain relationship inside. Even we accept there should have a subject for ‘thinking’, that subject is not necessary to be ‘I’.
Descartes’ Knowledge Skepticism and Its Criticism