The Move from Doubt to Certainty; A Look at the Theories of Descartes and Locke Descartes is interested in the certainty of his existence and the existence of other people and things. Descartes' beliefs vary from those of Socrates. Descartes argues that knowledge is acquired through awareness and experience. Using this approach, Descartes moves through doubt to certainty of his existence. He asks himself various questions about the certainty of his existence and solves them through clear thought and logic. Using this method Descartes establishes doubts to be truths and by the end of the book, he has established that he does indeed exist.
In this paper, I will show how Descartes moves through doubt to certainty. I will explain how Descartes uses the cogito, proves the existence of God and what that means to his existence. I will also discuss the general rules of truth that Descartes establishes. In the First Meditation Descartes begins to examine what is certain and what is doubtful. Descartes wants to establish that his knowledge is certain and not doubtful.
He states, ... I had accepted many false opinions as being true, and that what I had based on such insecure principles could only be most doubtful and uncertain; so that I had to undertake seriously once in my life to rid myself of all opinions I had adopted up to then, and to begin, and to begin afresh from the foundations, if I wished to establish something firm and constant in the sciences. (Descartes 95) By this Descartes means that he wishes to establish a foundation for his knowledge based on certainty instead of doubt. Descartes first looks at the senses.
This is important because the senses are the first thin to cause doubt. He focuses on the perception of things. He says that things far from him, in the distance, give him reason to doubt their certainty, while things that are close to him are indubitable and he is clear about their certainty. However, Descartes realizes that dreams pose an obstacle to his beliefs. Even up close, dreams can be indubitable.
Descartes believes that if a person has had a dream that was so intense that the person could not determine it form reality, then they have reason to doubt objects that are close to us and appear to be indubitable. In order to resolve this problem, Descartes suggests that one must examine whether they are dreaming or not. Descartes realizes that he can not rely on his senses anymore to give him dubitable truths. He turns to find something that is indubitable. Descartes tries to use science as a foundation for truth. He discards physics, astronomy, and medicine because all three of them rely upon the senses.
.".. we shall not be wrong in concluding that physics, astronomy, and medicine, and all the other sciences that depend on the consideration of composite things, are most doubtful and uncertain... ." (Descartes 98). However, Descartes finds that such things as geometry and arithmetic can be trusted because their are no senses involved. They are based upon logic.
.".. whether I am awake or asleep, two and three added together always makes five, and a square always has four sides; and it does not seem possible that truths so apparent can be suspected of any falsity or uncertainty" (98). However, Descartes finds reason to even doubt this. The only thing that could makes these truths dubitable is through the intervention by an Evil Deceiver (God). Descartes cannot prove that God is good and has to acknowledge that God has the power to deceive. Therefore, Descartes must doubt all things until he can prove their certainty.
Descartes comes to call this doubt Universal Doubt. In the Second Meditation, Descartes examine the existence of himself. He concludes that if he cannot prove something exists then how does he know with certainty that he exists. It is his doubt of his existence that Descartes uses to prove his existence.
Descartes realizes that if he is able to doubt then he does indeed exists. He take the approach that, "I think therefore I am" to establish a certainty that he exists. This idea also known as the cogito becomes the central point that Descartes will use for the remaining of his meditations. Descartes affirms his existence every time he thinks, doubts, or is persuaded (Descartes 103). Descartes affirms that if there is an Evil Deceiver then Descartes must exist because in order for God to deceive, Descartes he must first exist. Although, Descartes has proved his existence he can only prove it in the mental capacity.
He does not know for certain that he exists in the physical form. The only way, at this time, that Descartes can prove the existence of his body is through his senses. He has already established that his senses are dubitable and therefore cannot tell him with certainty that his body exists. In order to get a better understanding of his relationship between his body and mind, Descartes melts a piece of wax. He observes the wax in two different states, the first in a solid form and the second in a melted form. He questions how his senses can show him two entirely different forms of the same substance; yet he knows that the substance, in both states, although completely different, is wax.
The mind was able to understand the essence of the wax. Although the senses were not entirely capable of making the connection between the two forms of wax, the senses assisted the mind in determining what the substance was. This experiment proves to be important to Descartes because he is able to make a link between the senses and the mind. Using his experiment, Descartes enters his Third Meditation using his general rule of truth that ."..
all things we conceive very clearly and distinctly are true" (Descartes 113). However, there is one flaw to his thoughts. If God is an evil deceiver than this cannot be true. Descartes proceeds to establish that God is good and does not deceive. Descartes uses three points to establish the existence God.
These points are ideas. The first one is adventitious ideas; those ideas that come from outside experiences. The second is invented ideas; those that are derived from the imagination such as sirens and chimera. The final is innate ideas; those that are within one when they are born. Descartes uses two more points to further establish that God exists. He uses the ideas of "infinite" and "perfect." These two ideas, Descartes cannot account for.
The only way for such things to come about would be from an infinite and perfect being such as God. These ideas have a direct relationship with God. In order for a finite beings such as Descartes to have a concept of infinite it must have been planted there by an infinite being such as God. Descartes concludes this idea to be true because one cannot derive the idea of infinite by negating the finite (Descartes 125). An example of this would be the use of a number line. The number line will never be able to illustrate infinity.
One could negate every number on a number line and still not arrive at infinity. Therefore, Descartes concludes that God does exist and therefore is not an evil deceiver. Because God has supplied us with the innate ideas of perfection and infinity, God, therefore, must be infinite and perfect. Descartes states that, "Whence it is clear enough that he cannot be a deceiver, for the natural light teaches us that deceit stems necessarily from some defect" (Descartes 131). Since God is perfect he is not an evil deceiver. It is important to realize that by the time Descartes has reached his Fourth Meditation he has proved three important things.
The first is that doubt is not universal. The second is that there is a general rule of truth. The third is that God exists and cannot be an evil deceiver. However, Descartes raises a question: If God exists and cannot be an evil deceiver then why are humans imperfect and perpetually making errors Descartes explains this through the explanation of free will. Descartes states that God has given all humans free will.
This is the cause of human error. Because we have free will, humans are able to make choices and decisions free from the influence of God. Sometimes free will interferes with God's ability to help humans and therefore humans sometimes make poor decisions. If God did not give humans free will than God would play a direct role in every decision made by humans. It is because God gives humans free will that allows for human error. Descartes Fifth and Sixth Meditations begins with the establishment of his remaining doubts and the application of what he has discovered.
The first question deals with the essence of color, mathematical, and geometrical truths. The second is the existence of people and things. The third is determining the difference between dreams and reality. Descartes reiterates that God is not an evil deceiver and therefore he can clearly conceive something to be true. He reiterates that if he conceives God correctly then God is perfect. Imperfection is not compatible with God's omnipotence.
A non-existent thing cannot be perfect. Even a non-existent perfect thing is imperfect and all perfect things are perfect. Descartes also restates that a perfect thing cannot deceive. With this knowledge, Descartes proceeds to solve his second problem. The existence of corporeal (physical things) exist with certainty. Since God is not an evil deceiver, the idea of physical things is accurate.
Although some perceptions will still be blurry and may confuse Descartes objects do indeed exist. He concludes that he just has to be more judgmental of those perceptions. But as concerns other things, which are either only particular, as, , for example, that the sun is of such a size and shape, etc. , or are perceived less clearly and distinctly, as in the case of light, sound and pain and so on, although they are very doubtful and uncertain, nevertheless, from the fact alone that God is not a deceiver, and has consequently permitted no falsity in my opinions... (Descartes 158) Descartes now knows for certain that he has a body. Descartes realizes that, ."..
I have a body, which is ill disposed when I feel pain, which needs to eat and drink when I have feelings of hunger or thirst etc." (Descartes 159). Because of these feeling that Descartes has and because God is not an evil deceiver than Descartes is indeed lodged in a body and is an entire entity with it. Descartes finally analyzes his third doubt. He now has the ability to distinguish between being awake and dreaming. When we are awake, Descartes states, are mind flows in an uninterrupted, continuous sequence. When we are dreaming, our mind does not flow in a consistent, and undisturbed sequence.
When a person has a break in the consistency of events, they are dreaming... when I perceive things which I clearly know both the place they come from and that in which they are, and the time at which they appear to me, and when, without any interruption, I can link the perception I have of them with the whole of the rest of my life, I am fully assured that it is not in sleep that I am perceiving them but while I am awake (Descartes 168) After establishing certainty to his doubts, Descartes states, "And I must reject all the doubts of the last few days as hyperbolic and ridiculous, particularly the general uncertainty about sleep, which I could not distinguish for a wakeful state... ." (Descartes 168). With that Descartes concludes his meditations and uncertainties. Although Descartes makes a sound argument there were some people that disagreed with his theories. One of those people was John Locke.
The beliefs of Locke, who was an empiricists, were similar to those of the Sophist during the time of Socrates. He argued that when a person was born their mind was empty. A person obtained knowledge through experiences. He also felt that if a person misinterpreted an experience it could lead to doubt or skepticism.
Locke tries to prove Descartes wrong by saying that there are no innate ideas. He states that by understanding our own mind we can deter doubt. Locke proposes three separate possibilities about truth. The first is that there is no such thing as truth. The second is that there is no way to obtain truth. The third reason is that we can understand implied things but not be absolutely certain about them.
Locke believed that we never deal with certainty and everyday we deal with possibility... and it will be unpardonable, as well as childish peevishness, if we undervalue the advantage of our knowledge and neglect to improve it to ends for which it has given us, because there are some things that are set out of the reach of it. (Locke 57). Locke states that not all innate ideas come from "natural ability." He says that a universal consent does not prove innate ideas. They could arise from experience. Locke supports this theory by saying that innate ideas are neither in children nor idiots.
If these ideas were innate then everyone would have them. He further states that mathematical truths are learned from experience and are not innate ideas. Descartes and Locke were two men with completely different views. They each set out to prove their own existence in a different fashion. Although they do not agree with each other, each one of them presents a clear and intelligent argument. It is these arguments that have encouraged the human race to consider the possibility of existence long after the death of Descartes and Locke.
People will continue to debate their viewpoints for years to come and maybe, one day we will know the meaning of existence. Descartes, Rene. Discourse on Method and the Meditations. Trans. F. E.
Sutcliffe. New York: Penguin, 1996. Locke, John. An Essay Concerning Human Understanding.
ed. Roger Wool house. New York: Penguin, 1997.