René Descartes - The Discourse on the Method

René Descartes(1596 –1650) interest in method was shared by many sixteenth and seventeenth century scientists, mathematicians and philosophers. One source of this interest in method was ancient mathematics. The thirteen books of Euclid's Elements was a model of knowledge and deductive method. But how had all this been achieved? Archimedes had made many remarkable discoveries. How had he come to make these discoveries? The method in which the results were presented (sometimes called the method of synthesis) was clearly not the method by which these results were discovered. So, the search was on for the method used by the ancient mathematicians to make their discoveries (the method of analysis). Descartes is clearly convinced that the discovery of the proper method is the key to scientific advance. 

His analytic method of thinking focused attention on the problem of how we know (epistemology), which has occupied philosophers ever since.He became dissatisfied with the unsystematic methods utilized by the previous authorities in science, since he concluded they had not "produced anything which was not in dispute and consequently doubtful" . The only exception to this was in the field of mathematics which he believed was built on a "solid foundation" . Medieval science, on the other hand, was largely based on authorities from the past rather than observations in the present, therefore Descartes decided to conduct a personal plan of investigation. But, for Descartes, even his personal observation of the "book of nature"  was not sufficiently beyond doubt because of his concern about the "deception of the senses." After consideration of all the previous methods of inquiry Descartes decided that there must be a better way; and in his Discourse on Method he wrote, "I eventually reached the decision to study my own self, and choose the right path" 

Descartes aspired to rebuild a new system of truth.He believed that he could then use his new method of reasoning to build on such a first principle, ultimately leading to the unification of all knowledge. He calls into question everything that he thinks he has learned through his senses but rests his whole system on the one truth that he cannot doubt, namely, the reality of his own mind and the radical difference between the mental and the physical aspects of the world.

A summary of "Discourse on the Method of Rightly Conducting the Reason, and Seeking Truth in the Sciences".

1.All people possess “good sense,” the ability to distinguish truth from fiction. Therefore, it is not a lack of ability that obstructs people but their failure to follow the correct path of thought. The use of a method can elevate an average mind above the rest, and Descartes considered himself a typical thinker improved by the use of his method. Descartes benefited from a superior education, but he believed that book learning also clouded his mind. After leaving school, he set off traveling to learn from “the great book of the world” with an unclouded mind. He comes to the conclusion that all people have a “natural light” that can be obscured by education and that it is as important to study oneself as it is to study the world.

2.He considers that the science he learned as a boy is likely flawed because it consists of the ideas of many different men from various eras. Keeping in mind what he has learned of logic, geometry, and algebra, he sets down the following rules: 

- The first rule was never to accept anything as true unless I recognized it to be evidently such: that is, carefully to avoid precipitation and prejudgment, and to include nothing in my conclusions unless it presented itself so clearly and distinctly to my mind that there was no occasion to doubt it.

- The second was to divide each of the difficulties which I encountered into as many parts as possible, and as might be required for an easier solution.

- The third was to think in an orderly fashion, beginning with the things which were simplest and easiest to understand, and gradually and by degrees reaching toward more complex knowledge, even treating as though ordered materials which were not necessarily so.

- The last was always to make enumerations so complete, and reviews so general, that I would be certain that nothing was omitted.

In short, his method required (1) to never believe anything unless he can prove it himself; (2) to reduce every problem to its simplest parts (breaking a problem down into parts); (3) to always be orderly in his thoughts and proceed from the simplest part to the most difficult - deducing one conclusion from another; (4) to always, when solving a problem, create a long chain of reasoning and leave nothing out. He immediately finds this method effective in solving problems that he had found too difficult before.

3.Descartes puts forth a provisional moral code to live by while rethinking his views:

(1) to obey the rules and customs of his country and his religion and never take an extreme opinion;

(2) to be decisive and stick with his decisions, even if some doubts linger;

(3) to try to change himself, not the world; and

(4) to examine all the professions in the world and try to figure out what the best one is. Not surprising, Descartes determines that reasoning and searching for the truth is extremely important and useful. For many years after his revelation, Descartes traveled widely and gained a reputation for wisdom, then retired to examine his thoughts in solitude.

4.Descartes offers proofs of the existence of the soul and of God. Contemplating the nature of dreams and the unreliability of the senses, he becomes aware of his own process of thinking and realizes it is proof of his existence: I think, therefore I am ( Cogito ergo sum - A philosophical proof of existence based on the fact that someone capable of any form of thought necessarily exists).Descartes concluded, if he doubted, then something or someone must be doing the doubting, therefore the very fact that he doubted proved his existence. "The simple meaning of the phrase is that if one is skeptical of existence, that is in and of itself proof that he does exist." He also concludes that the soul is separate from the body based on the unreliability of the senses as compared with pure reason. His own doubts lead him to believe that he is imperfect, yet his ability to conceive of perfection indicates that something perfect must exist outside of him—namely, God.

5.Descartes considers the fact that animals have many of the same organs as humans yet lack powers of speech or reason. He takes this difference to be evidence of humankind’s “rational soul.” He considers the mysterious connection of the soul to the body and concludes that the soul is different and separate from body. Therefore it must not die when the body dies. Because he cannot conceive of a way that the soul could perish or be killed, he is forced to conclude that the soul is immortal.

Gist :

• Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.
• It is not enough to have a good mind. The main thing is to use it well.
• The greatest minds are capable of the greatest vices as well as of the greatest virtues and those who travel very slowly may yet make far greater progress, provided they keep always to the straight road, than those who, while they run, forsake it.
• Never accept a thing as true until you knew it as such without a single doubt.
• Divide each difficulty into as many parts as is feasible and necessary to resolve it.
• Make enumerations so complete, and reviews so comprehensive, that one should be certain of omitting nothing.
• Each problem one solves becomes a rule, which serves afterwards to solve other problems.
• I think, therefore I am -- I think therefore I exist.