Descartes' Meditations

Descartes' meditations are created in pursuit of certainty, or true knowledge. He cannot assume that what he has learned is necessarily true, because he is unsure of the accuracy of its initial source. In order to purge himself of all information that is possibly wrong, he subjects his knowledge to methodic doubt. This results in a (theoretical) doubt of everything he knows. Anything, he reasons, that can sustain such serious doubt must be unquestionable truth, and knowledge can then be built from that base. Eventually, Descartes doubts everything. But by doubting, he must exist, hence his "Cogito ergo sum".

It is from this thought that Descartes is able to determine God exists and create his first argument for this idea in the Third Meditation. He does this by beginning with the only thing he knows to be true: That, through doubt, he must exist. By knowing he doubts, he then knows that he doesn't know everything. This make him imperfect. But to know you are imperfect, Descartes reasons, must mean that you have a concept of perfection (Thomson 26). This allows him to verify how he has a rational idea of a prefect being, God.

Knowing that he has an idea of perfection, Descartes continues to prove God's existence by assuming everything must have a cause. This is known as the Principal of Sufficient Reason. For Descartes, this principal allows the acceptance of another, called the Principal of Sufficient Reason. "There must beat least as much reality in the total efficient cause as in the effect" (Thomson 27). He gives an analogy of heat, and how heat cannot be produced in an object devoid of heat unless it is acted upon by something containing a greater amount of heat (Baird, Kaufmann 33). And because Descartes refutes the idea of infinite regression, God must be the initial cause.

He also claims God as the cause of his idea of God. He reasons that, through these principals, his idea of God cannot have come from himself, as he is an imperfect being. He does not have the capability of thinking of an infinite substance or a perfect substance, such as God, because he has lesser reality than these ideas and cannot be the cause of them. The only way these ideas could exist is if they were created by something of equal (greater being impossible, as infinite perfection cannot have a superior) reality. Because God is the only infinite Descartes can recognize at this state, it must be God that planted the idea in his mind.

Descartes' first argument for the existence of God can be summarized as follows:

2)There are two forms existence- contingent and necessary

3)Necessary existence has greater reality than contingent

4)A perfect being must have necessary existence

5)A perfect being must exist, if it has necessary existence

This allows Descartes to begin to gain true knowledge, because his perfect being exists and would not allow him to be deceived all the time because perfection does not allow for that behavior.

In the Fifth Mediation, Descartes purports his ontological argument for the existence of God. It is simpler than his first and based on God's essence. For anything else that exists, the essence of that thing only implies it's existence. For God, however, essence is existence. God is perfection, and existence is a type of perfection. So an absence of existence would be an absence of perfection, which is impossible in God.

Descartes' second argument for the existence of God is then:

1)By definition, God has all perfections

Despite his efforts to remove all imprecise information from his thoughts, Descartes' proofs of God have some errors, or at least shortcomings, that have been pointed out over time.

One problem with his first proof is his idea of God. To see where the fallacy lies, an understanding of Descartes' understanding of ideas is needed.

"Now as far as ideas are concerned, provided they are considered solely in themselves and I do not refer them to anything else, they cannot strictly speaking be false; for whether it is a goat or a chimera that I am imagining, it is just as true that I imagine the former as the latter." (Baird & Kaufmann 31) "Thus the only remaining thoughts where I must be on my guard against making a mistake are judgments. And the chief and most common mistake which is to be found here consists in my judging that the ideas ideas which are in me resemble, or conform to, things located outside me" (Baird & Kaufmann 31)

Descartes formed an idea of God as an infinitely good being. He would have had to discover this idea within his own mind. According to his principle of universal doubt, he cannot simply know whether his conception