1. René Descartes
Brandon Lee
Block D

2. Born March 31, 1596 in Indre-et Loire, France
Died February 11, 1650
Aside from being a philosopher, was also a physicist and a mathematician; he had a large influence with the progression of mathematics.
Most of his main philosophic ideas were in his book, Discourse on the Method of Rightly Conducting One's Reason and of Seeking Truth in the Sciences

3. A New Model For Thinking
Decided that, since math has certainty, we should base a model off of it for human knowledge.
He proposed a new system of thinking, in which a person would only accept what they were absolutely certain was true.
However, in order for the system to work, one would have to throw away all of the previous beliefs they ever had through experience, culture and education.

4. The Rules of Descartes’ Philosophical Model
Descartes made a new set of rules for this way of thinking. They are often referred to as a rationalistic approach.
Accept only what can be established beyond any doubt as true.
Divide every question into manageable parts
Begin with the simpler issues before working on the more complicated ones.
Check back and review what has already been done to make sure one’s ideas still make sense.

5. Method of Doubt
As mentioned before, Descartes planned to create a new base of knowledge, from the ground up. To do this, he applied a method of doubt.
He decided to begin by doubting everything he ever knew or would know, including the evidence from his senses and reasoning itself.
His logic was that if any thought or truth about the world could survive this challenge, then it surely must be undeniably true and a good starting foundation for knowledge.

6. Perceptual Illusion
He began by doubting any thing that came from his senses.
He reasoned that things are not always what they may look like/sound like/ etc. at first.
Since one corrects their mistaken ideas perceived from their senses by referring to previous perceptions by the senses thought to be correct, one cannot trust their senses, since the “correct” perception could also be mistaken.

7. Doubt of Dreams
When thinking about how he may be deceived by his senses, Descartes found another reason to doubt the truthfulness of his senses.
He reasoned that, since he often could not tell his most vivid dreams apart from reality when he was awake, it is possible that everything he thinks about the world around him is nothing more than a production of his own mind; just another dream.
With this idea, he found it possible to doubt the existence of any physical thing and outside world at all.
This is the same concept as that explored in the movie Inception

8. The God Hypothesis
Descartes asks the reader to consider the idea of a god who is omnipotent. However, that god devotes all of its attention to deceiving him.
This means that whenever he believed anything true, the deceiving god, would change the world at that moment to make the belief false.

9. Cogito, Ergo Sum
With his last ideas presented, it seemed Descartes was saying nothing could be certain.
Descartes says no to this and says the phrase “cogito, ergo sum.” ( I think therefore I am).
He reasoned that, thought does not depend on the reality of an external world and it would still have to exist, even if it was being deceived.
Descartes associates his thought with his consciousness awareness, so, since his thought exists, he must exist as well

10. Source of Ideas
Descartes stated that the reliability of our thoughts and ideas depend on where they come from.
He gave only three possible sources:
All ideas enter the mind from the outside world.
All ideas are made by the mind itself
All ideas are innate (placed in the mind by God)
However, with his method of doubt, Descartes cannot yet know if an outside world actually exists and his mind can imagine virtually anything so everything depends on whether a god exists or not.

11. The Existence of a God
He began with the starting point that any idea must have the same amount of reality as the contents of the idea itself.
He figured, that since his idea of a god had content that was unlimited, the cause of that idea must be unlimited and infinite.
He says that the idea of a god cannot be produced externally or inside his own mind, since one cannot direct experience contact with a god or find the concept of perfection in themselves, so the idea must be put there by a god.
To add to his claim, Descartes refers to a cosmological argument saying that since he knows he exists and is in no way perfect, he cannot cause himself and so begins a chain of causes and things that caused them, which must eventually end with an ultimate perfect self caused god.
As to Descartes idea of a deceiving god, he reasons that it would not be possible since, deception is a product of imperfection, it stands to reason that the god would have no reason or motive to deceive him.

12. Cartesian Dualism
One of Descartes most famous ideas was that of dualism.
He found that it was possible for him to doubt the existence of his body, since he could just be dreaming he had one or it could be an illusion from an omnipotent being. However, he could be sure he had a mind.
This led Descartes to the conclusion that the mind and body must be two separate and distinct substances.
He said that while arm and leg could be separated and divided from the body, his mind and soul were inseparable.
From this, Descartes decided that the mind must be an immaterial substance that was the essence of himself, one that doubted, believed, hoped and thought.

13. Works Cited
"DESCARTES, René." (n.d.): Funk & Wagnalls New World Encyclopedia. EBSCO. Web. 22 Sept
Chew, Robin. "René Descartes | Philosopher." Lucidcafé Interactive Café and Information Resource Web. 22 Sept
"Rene Descartes." Rene Descartes Web. 22 Sept <
Skirry, Justin. "Descartes, Rene: Overview [Internet Encyclopedia of Philosophy]." Internet Encyclopedia of Philosophy. 13 Sept Web. 22 Sept <
"Rene Descartes." Wikipedia, the Free Encyclopedia. 20 Sept Web. 22 Sept <
Kermerling, Garth. "Descartes." Philosophy Pages. 9 Aug Web. 22 Sept <