by Nikki Albert

Created on: December 02, 2010

Rene Descartes' epistemology is a rationalist philosophy opposed to empiricism which is laid out in his Meditations on First Philosophy. He begins this process by eliminating all things that can be doubted in order to find that which cannot be denied to establish a foundation. “I must once and for all seriously undertake to rid myself of all the opinions which I had formerly accepted and commence to build anew from the foundation.” (165). This is referred to a methodological doubt where everything is to be doubted even that which is almost certain. If it can be doubted, then it should be.

The senses are known deceivers. For one thing there is no philosophical proof that at any moment we are not dreaming. We can be deceived by illusions. We cannot know reality through our senses when our senses may tell us what appears to be there rather than the truth. So we must doubt our senses and because at any moment we could be dreaming, we must doubt the external world.

Yet with mathematics, whether we are dreaming or not, 2 +2 = 4. This is a priori and thus known independent from observation. Descartes uses the idea of an evil genius to progress with this radical doubt. It goes like this: How do I know the universe was not in fact designed by a malevolent being whose only goal is to deceive me. Every time I make some simple mathematical judgment, I am wrong, yet never know that I am. Because this cannot be disproved math is not absolutely certain.

What then cannot be doubted when an evil genius may plant false knowledge in us? Nor if we are mad or dreaming? Descartes realizes no matter what he knows he exists. “I am, I exist, is necessarily true each time that I pronounce it, or that I mentally conceive of it.” (171). Our self is our mind, our soul and a thing that thinks. This is our solid foundation, but how do we get the external world or our body back into what can be known? Descartes states we must be rid of the evil genius. The only way to be rid of this possibility is to prove the existence of God, since God would not deceive us.

Descartes' proof for the existence of God goes thus:

1) A being who doubts is an imperfect being.

2) I doubt, therefore I am an imperfect being.

3) Yet I can only be aware that I am imperfect by having the concept of perfection. Therefore, I do have the concept of perfection.

4) I could not have gained the concept for perfection from something that is imperfect. Therefore, the concept is not derived from my own reasoning.

5) Therefore my concept of perfection must come from something perfect.

6) Only God is actually perfect, so I derive my concept of perfection from him, and therefore, he exists.

Whether or not we agree with his proof for God’s existence, it is necessary for Descartes' argument, for by proving God’s existence we banish the possibility of an evil genius. Since the possibility of an evil genius was the only reason to doubt mathematics, mathematics is now valid. Since our innate ideas likewise were not planted within us by a malevolent being, they have the possibility of being valid. We also know that the external world, and our bodies, actually exist because God would not deceive us. However, our senses and perceptions of that reality can be faulty and imperfect, thus we must rely on science and mathematics to verify the external world. Since it is the mind or soul that is fundamental, Descartes is a dualist, believing that the mind is separate from the body.

Notes:

Descartes, Rene Meditations on First Philosophy

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