In the Fifth Meditation, Descartes presents his second argument for the existence of God. Descartes argues that existence is perfection and therefore can be a predicate for God. I will first explain what the ontological argument for the existence of God is. Next, I will explain why Descartes decides to introduce God into his method of philosophy. I will then try to demonstrate that existence is a perfection and that as a predicate of God, existence reveals certain truths about God. Ontological argumentation attempts to prove the existence of God from an a priori perspective, that is, an idea implanted in the human mind by God. se. The argument therefore depends on analytical reasoning, from premise to conclusion. Descartes believes he has an innate idea which he calls “innate” (p. 43). His ability to think did not bring about the idea in his mind, but God's free will to act. So, as the idea intuitively manifests itself to one's mind; it reveals something about its author. The idea allows Descartes to think of a perfect being that must necessarily exist, namely God. In his epistemological quest for truth, through thought experiment, Descartes' Meditations offer the reader a method of doubt that could be used to discover what is absolutely certain, and free oneself from errors caused by errors of judgement. Descartes' goal is to find an indubitable truth. He uses the method of hyperbolic doubt to establish an absolute and convincing foundation of truth. He discovers that sensory experience can be doubted, but Descartes cannot doubt that he really doubts. Moreover, he fears deception in everything. However, he cannot be deceived about his own existence since to be deceived, one must first exist. “I think, therefore I am”. I...... middle of paper......a triangle has three sides, so the idea of ​​God includes His existence. Since Descartes was able to prove the existence of God, he maintained that man can have confidence in his clear and distinct idea and reason. Since God is perfect, he cannot be a deceiver; if he did so, it would undermine his nature. Therefore, the rational mind can now be certain of the clear and distinct truth. Works Cited Beardsley, Monroe C. European philosophers range from Descartes to Niectzsche. New York: Rondom House, Inc. 2002. Holt, Tim. “Existence is not a predicate.” ©2008. Access: Access, November 8, 2011. http://www.philosophyofreligion.info/Robinson, Timothy A. God. 2nd ed. Indianapolis: Hackett Publishing Company, Inc. 2002. Ross, Kelley L. “The Beginning of Modern Science.” ©2010. Web.Access, November 12, 2011. 2010http://www.friesian.com/hist-2.htm#descartes