Descartes Meditations can be described as doubt unleashed. He doesn’t think we know very much, though he is sure we know something. Russell and Moore, especially Moore, thinks we know quite a bit of useful stuff. Cornman et al seem to agree. What does Descartes’ method of hyperbolic doubt show that we really know? Is that all? Is that really all we know?
Knowledge on Existence of Human Beings and External World
Introduction
Descartes’ method of hyperbolic doubt shows that we really know of our own existence as thinking beings. He trusts that what should be doubted is that which is not certain. However, I strongly believe this is not all we as human beings know since there are other things that exist far from our minds. This is because through reasons, science, commonsense, justification and proof, human beings have a lot of knowledge which entails existence of matter and objects. Despite the fact that we may hold similar knowledge on our own existence, we definitely know much on the existence of external world.
Knowledge through Sureness
Descartes asserts that the only thing that human beings know about is their own existence. Otherwise other things can contain some acts of deception. This means that everything that is known outside human mind could be a mistake. The mind is the focal point of knowledge on human existence as thinking beings according to Descartes. But how can we justify the existence of a mind that is separate from the body. I believe that we as human beings have more knowledge about existence of the external world than what Descartes put it. He argues that he is quite certain of his existence as a thinking being but the question is how it is possible for the mind to function alone without the body. He further declares that the mind exist as a complete thing which cannot not be separated like body parts which can be independently alienated. I suppose there must be some form of object which holds human mind since it must exist in a vat. Through reason and commonsense, we can ascertain that the body exists so as to hold the brain in place. This is because the brain exists in human body and not outside our bodies. It is interesting to see that Descartes supports the fact that the mind and body are related in the sense that the human mind is influenced by the body in perception and at the same time bodies are influenced by minds in actions. From this notion, I am left to wonder how a thinking object can solely exist without the body which apparently influences it. With this in mind it is possible that we do not only know about the existence of human beings as thinking beings but also as human beings with bodies that guide our minds into doing things. Descartes gives an example of lifting his hands which according to him is instigated by the brain. We can confirm that the brain is caused by the desire to lift the hand. By this I mean that, the desire to lift the hand is the cause, while lifting of the hand is the effect. From this prospect we can deduce that everything that is in existence has a cause and effect. Therefore for the brain to be in existence, there must a cause that existed before the brain which I believe is the body. It is therefore evident that there is much that we know apart from the existence of human beings as thinking objects.
Knowledge through Perceptions
Descartes just like Bishop Berkeley offers a basis of knowledge by arguing that human beings can be in a position to know things through sensible qualities or our own perceptions. He has no doubt that he exists as a thinking being. Nevertheless, If we can gain knowledge on existence of things through our perceptions what about those things which cannot be perceived through human mind? To assert that the knowledge of subsistence of things can be done through perceptions means that matter does not exist .This is because what can not be perceived in our own mind according to Descartes’ belief, is not in existence. It is worth noting that Descartes assertion that he exists as a thinking being with a separate body is supported by his conviction that a certain supreme force exists. Of note is why he can account on the existence of an infinite force. Are there justifications to support his convictions? On the other hand, for human beings to have full knowledge of things there must be an account that supports ones sentiments. For instance, Descartes has no doubt about his own subsistence due to a particular force. How does he know this supreme force exists? Are there accounts of things that make him believe that truly a certain supreme force is in existence? Even though Plato’s account of knowledge has some limitation in the sense that every belief held by people can be justified even if it was wrong, Descartes reality of supreme force is not proven and there is no justification of existence of an infinite power whatsoever. Descartes believes that his mind exists because he exists the way he is and because an infinite being exists but he fails to give account of the existence of this infinite being. From these ideas, I believe we know much of things especially when we can offer justification, constituent and differentiation of their existence.
Knowledge through Justified True Beliefs (JTB)
We do not only know what is certain, there are other things that have justified true beliefs (JTB) that we can as well have knowledge about. However, this method requires no skepticism. If we accept as true the things we suppose we believe and there are some forms of reasonable justifications for our beliefs, then we have much knowledge on other things apart from our own reality as well as existence of the external world.
Knowledge through Reason, Commonsense and Science
Descartes is skeptic about the existence of human body. He is also skeptical about existence of external world which we can evidently easily use our common sense to realize. He believes that we know of our own existence because it is certain. I beg to differ with him since we can for sure use our sense to gain knowledge of the external world. There are things which we can see in reality. According to Russell we know of reality of sense-information which triggers our thoughts in the external world. Nonetheless, his thoughts are similar to Descartes who asserts that matter exists in mind. Therefore if the mind does not exist then matter is also not in existence. This argument is not reasonable enough since the reality of things does not change when our sense-data is in active. By this I mean, if a put a cup on the table and then cover it, does it mean by covering the cup, the cup has seized to exist? As a result we have plenty of knowledge that is build on our natural believe as opposed to sense data. Moore on the other hand asserts that we have knowledge about existence of external world through things we can prove practically. Chisholm also stresses that we know a lot of things through reason, common sense as well as science. He put a challenge on how human beings understand or knows good and bad. I think from his sentiments, we have plenty of knowledge on procedures, process and reliable sources that helps in telling what is true or false.
Conclusion
Descartes believes that human beings have knowledge of their existence as thinking beings. According to him we should only consider that which is certain. However, apart from the knowledge of our own being, there are other knowledge we have as human beings which is instigated through commonsense, science, proof and reason. Therefore it is evident that we may hold similar knowledge on our own existence but we definitely know much on the reality of external world.
