Rene Descartes asserts that our most fundamental beliefs are uncertain, and consequently, all beliefs resting on these basics are also uncertain. In his First Mediation, he sets out to determine which beliefs are certain and which are doubtful. Descartes applied illusion argument, dreaming argument, and evil genius argument. Descartes method of doubt is practically about sorting out our beliefs and keeping the only absolute beliefs, which cannot possibly be false. Descartes states "...because undermining the foundations will cause whatever has been built upon them to fall down of its own accord--I will at once attack those principles which supported everything that I once believed." Descartes is saying that because of the weak foundations he built will fall on its own sooner or later therefore, he will "at once" attack his principles. In dream argument Descartes argues which casts doubt on the truth on our intellectual beliefs. So, I know it's raining because I have perceptual belief that it's raining. "How often has my evening slumber persuaded me of such customary things as these: that I am here, clothed in my dressing gown, seated at the fireplace, when in fact I am lying undressed between the blanket." In this sentence Descartes is trying to explain that many times we dream and what we dream seems very real. According to Descartes structure of the reasoning goes like this: (A) It looks to me that it's raining (B) So, I know that it's raining The dream argument casts doubt on the transition from A to B assuming that we cannot know what we can doubt. (A) It looks to me that it's raining (C) If I am dreaming then it will look to me that it's raining when it's not really raining. So, I cannot be certain that it's raining because it could be just a dream. The second argument Descartes used is evil genius existence. Descartes used propositions of math because math problems as 7+5=12 does not rely on our senses justification. Desc...