KIRK ROBERTS REBOROSO THEORIES OF KNOWLEDGE

II- PHILOSOPHY DR. PAOLO BOLANOS

RENE DESCARTES’ METHODIC DOUBT

Introduction:

Rene Descartes is widely considered as the father of modern philosophy. His

remarkable contributions extended to mathematics and physics. This entry focuses

on his philosophical contributions in the theory of knowledge. Descartes' pursuit of

mathematical and scientific truth soon led to a profound rejection of the scholastic

tradition in which he had been educated. He is a rationalist, in a way that he view

knowledge as innate or inborn and comes from the mind alone. Knowledge for him

doesn’t come from the use of the five senses. Much of his work was concerned

with the provision of a secure foundation for the advancement of human

knowledge through the natural sciences. He lived from 1596 to 1650. He is a good

example of unconventional thinking leading him to new ideas and discoveries. His

background was mathematics, which to him gave certainty and definite

measurement capabilities. He wanted to apply these concepts that he learned in

mathematics to the natural world, but found that established rules and truths that

were the basis of geometry and mathematics were nonexistent in the natural world.

Instead, the views of the world held by most people were based on assumptions

that might not necessarily be true. He noted that people took things that they

learned in childhood as truth, without even thinking about or questioning them.

To get past being himself caught in the trap of preconceived ideas preventing

him from learning about the truth, Descartes started doubting any and all “alleged”

truths. This is called Methodic doubt, in which a person doubt everything, his

beliefs, ideas, thoughts and matter until he arrived at something that is

undoubtable, and then, we used it as a foundation of our knowledge. An analogy

for understanding the Methodic Doubt is the principle in jurisprudence that a

person is innocent until proven guilty. Descartes believes that ideas coming from

the senses are guilty until proven innocent. He showed that his grounds, or

reasoning, for any knowledge could just as well be false. Then he proposed the

stages of doubting process:

Problems:

1.) Senses

He said that our senses cannot be trusted. The senses are sometimes wrong and

many of our ideas come from the senses, therefore, many of our ideas could be

wrong. Sensory experience, the primary mode of knowledge, is often erroneous

and therefore must be doubted. For instance, what one is seeing may very well be a

hallucination. For example, from afar, you claim that you saw your father, but in

reality it’s your uncle. Thus, senses could trick us.

2.) Content of experience

Descartes said that, what if our experience is just only a dream. Descartes had

written that: “every sensory experience I have ever thought I was having while

awake I can also think of myself as sometimes having while asleep”. The problem

here is that how can someone prove that he is not dreaming. How can you

distinguish dreaming state from waking state? , this tentatively concludes that the

results of empirical disciplines are doubtful, for example, physics, astronomy,

medicine, and the like. Whereas: Arithmetic, geometry and other subjects of this

kind, which deal only with the simplest and most general things, regardless of

whether they really exist in nature or not, contain something certain and

indubitable. For whether I am awake or asleep, two and three added together are

five, and a square has no more than four sides. It seems impossible that such

transparent truths should incur any suspicion of being false. (Med. 1, AT 7:20)

Some attempts proving that one is awake:

-I know that I am awake because I can pinch myself.

=Fails because I can dream that I am pinching myself.

-I know that I,m awake because I remember going to sleep.

=Fails because I could have been dreaming that went to sleep.

3.) Mathematics

Mathematics survived in the dream state but not in the evil-genius hypothesis.

Although, if I am dreaming, I can still know that 2+2=4 and I know that all

triangles have three sides. Many people think that mathematics is the most exact

and precise. But what if there is a malicious demon or evil genius who simply

impose to our minds some mathematical operations. . Suppose I am the creation of

a powerful but malicious being. This evil genius or deceiving God, or whatever I

may call him,” has given me flawed cognitive faculties, such that I am in error

even about epistemically impressive matters — even the simple matters that seem

supremely evident. The suggestion is unbelievable, but not unthinkable. It is

intended as a justification-defeating doubt that undermines our judgments about

even the most simple and evident matters.

4.) Self

Descartes said that, What if I doubt my existence. What if I doubt that I exist?

Descartes said that, I have convinced myself that there is absolutely nothing in the

world, no sky, no earth, no minds, no bodies. Does it now follow that I too do not

exist? No: if I convinced myself of something then I certainly existed. But there is

a deceiver of supreme power and cunning who is deliberately and constantly

deceiving me. In that case I too undoubtedly exist, if he is deceiving me; and let

him deceive me as much as he can, he will never bring it about that I am nothing so

long as I think that I am something. So after considering everything very

thoroughly, I must finally conclude that this proposition, I am, I exist, is

necessarily true whenever it is put forward by me or conceived in my mind. (Med.

2, AT 7:25)

Response:

1.) Senses

In the Criterion of Truth, as long as you precede that it is clear and distinct, it must

be true. Senses, as long as you perceived things clearly and distinctly, they should

be reliable, otherwise, do not pass judgment. Descartes just want to say is that do

not accept unclear ideas.

2.) Content of Experience

Descartes offers a naturalistic solution to the problem (viz., a non-theistic

solution), in the form of a continuity test: since continuity with past experiences

holds only of waking but not dreaming, checking for the requisite continuity is the

test for ascertaining that one is awake. The following remarks can be read in this

way:

I now notice that there is a vast difference between the two “being asleep

and being awake”, in that dreams are never linked by memory with all the other

actions of life as waking experiences are. … But when I distinctly see where things

come from and where and when they come to me, and when I can connect my

perceptions of them with the whole of the rest of my life without a break, then I am

quite certain that when I encounter these things I am not asleep but awake. (Med.

6, AT 7:89–90)

3.) Mathematics

In the “I think, therefore I exist”, It draws that we are finite beings, that we are not

the cause of our own existence. Descartes strongly believes that there must be this

infinite being, which is God. And if God is evil, then what can we know? Answer:

I cannot know anything. Therefore, God is good. And if God is good, why God

made deceptive upon his name, which is s malicious demon. So, there is no

malicious demon. It concludes that mathematics is reliable.

4.) Self

Let’s remember few things about the Cogito Argument. The “I” is the mind, not

the body. Even if I cannot be certain of my senses or basic math, I can be certain

that “I”, which is the mind, exist. Here is a proof of Descartes’ argument: try to

deny the sentence “I am thinking”. If you deny the sentence, then you are forming

the belief “I am not thinking”. You have formed a contradiction because you

asserted P and -P. As Descartes writes: When someone says “I am thinking,

therefore I am, or I exist,” he does not deduce existence from thought by means of

a syllogism, but recognizes it as something self-evident by a simple intuition of the

mind. (Replies 2, AT 7:140)

Conclusion:

Important to note that:

-don’t accept unclear ideas, accept only information you know to be true.

-breaking down these truths into smaller units.

-solving the simple problems first.

-make complete lists of further problems or generalize.

References:

René Descartes, Meditation I, 1641

Hoffman, Paul, 1996. “Descartes on Misrepresentation,” Journal of the History of

Philosophy, 34 (July): 357–381.

Bennett, Jonathan, 1990. “Truth and Stability in Descartes' Meditations,” Canadian Journal of Philosophy, 16 (supplement): 75–108.

Stanford Encyclopedia.com

Special thanks to Sir Aldous Baccay