May 25th, 2000 Descartes sets about proving the existence of God through hismeditations on knowledge in an effort to prove the skeptics of his time wrong.He first determines that human knowledge is based entirely too much on unprovedpresuppositions. He argues that this makes it difficult to distinguish betweentruth and error, since we cannot recognize true knowledge. Descartes proposesthat the quest for knowledge must be based upon universal doubt. Specifically,he proposes the following in relation to his universal methodic doubt: 1.
Inorder to seek truth, it is necessary once in the course of our life, to doubt,as far as possible, of all things. 2. We ought also to consider as false allthat is doubtful. 3. We ought not meanwhile to make use of doubt in the conductof life 4. Why we may doubt of sensible things.
5. Why we may also doubt ofmathematical demonstrations. 6.
We cannot doubt of our existence while we doubt,and this is the first knowledge we acquire when we philosophize in order.Descartes proceeded to strip away his knowledge base in order to determine theone indubitable fact, “Cogito, ergo sum”. From this absolute knowledgeof his own existence, he set about deducing the existence of God throughontological argument. In our minds, the idea of God is one of an infinitelyperfect Being An infinitely perfect being must have existence, otherwise itwould not be infinitely perfect. Therefore, God exists. In proving theexistence of God, Descartes set the groundwork for determining that God createdman. He further postulated that God, being infinitely perfect and not adeceiver, could not have provided man with the deceptive powers of knowledge.Therefore, man’s mental faculties are determined to be trustworthy provided weseparate what there is of clear and distinct in the knowledge from what isobscure and confused.
Using this reasoning, man must discard all previousknowledge which is doubt-ridden, all sensory-based knowledge (as perceptions canbe misleading), and all intellection. As a result, skepticism is removed andvalid knowledge possible. Descartes primary purpose was the defense of humanknowledge against the attacks of the skeptics. He was justified in excludingpreconceived notions, presuppositions, and traditions in determining the limitsof knowledge.
Descartes discarded the ability of the mind to know truth and thehuman abilities of contradiction and sufficient reason. In doing so, he made asolution to the problem impossible. As it relates to his theory of the existenceof God, Descartes universal doubt refutes his own conclusion as to God’sexistence. Descartes formed an idea of God as an infinitely good being. He wouldhave had to discover this idea within his own mind.
According to his principleof universal doubt, he cannot simply know whether his conception of God iscorrect or incorrect. He would have, as a matter of his own principle,considered it as false until proven otherwise. Therefore, since the idea of Godis in doubt, the trustworthiness of man’s reasoning must also be doubtful andDescartes cannot escape his own real doubt. Descartes uses a process ofreasoning, a mathematical formulae, in attempting to demonstrate God’sexistence.
If his reasoning is of demonstrably doubtful validity, how canDescartes demonstrate God’s existence? The validity of Descartes reasoning issupposed to flow as a consequence of the infinite perfection of God; and God’sinfinite perfect is made certain through Descartes’ reasoning powers before hehas even proven that these reasoning powers are valid and trustworthy. Descartesassumes the very thing beforehand which he intends to prove afterwards. (Beggingthe question). Descartes accepts the trustworthiness of his faculties indemonstrating the existence and infinite perfection of God, and that isillegitimate.
A doubtfully valid faculty will produce a doubtfully validargument which will, in turn, produce a doubtfully valid conclusion. The entireargument for God’s existence is therefore nullified by a suspect reasoningprocess. Since he proves the reliability of his reason and process by means ofGod’s veracity, the proof of his reliability cannot be established beyond doubt.
Thus, Descartes attempt to vindicate the validity of human knowledge failed,because, by rejecting the reliability of his own powers to discover and knowtruth, he made it impossible for himself to remove himself from his ownuniversal doubt. Further, Descartes has marked inconsistencies in the manner inwhich he applies his procedure. He purports to reject everything in his pursuitof fundamental knowledge, even principles of contradiction and sufficientreason. In reality, he does not. He assumes the truth of these principles anduses them repeatedly. “Cogito ergo sum” is based upon the validity ofthe principle of contradiction. This principle states that it is impossible forsomething to be and not be at the same time.
Descartes becomes aware of his ownexistence by thinking or doubting. Why? Because he perceives that it isimpossible to think and not think and to exist and not exist at the same time.If he were consistent and seriously doubted the principle of contradiction, hewould have to agree that it is possible for an entity to think and not think, toexist and not exist at the same time. Then, according to his own supposition, hecould not be sure after all that the fact of his existence is certain. Only bygranting the validity and truth of the principle of contradiction beforehand,can his existence be established as an objective fact. That is exactly what hedoes. The same line of reasoning applies to his proof of God’s existence andinfinite perfection. Descartes rejection of the principle of contradictioninvalidates his arguments because, as long as this principle is not establishedand accepted, he could never be sure whether it would be possible for God toexist and not exist at the same time.
Similarly, Descartes would have to remaindoubtful as to whether God could be veracious and not veracious, deceiving andnot deceiving unless the principle of contradiction was taken for granted beforeDescartes begins to prove God’s existence. Descartes does not accept thisprinciple of contradiction throughout his reasoning. This is a glaringinconsistency in his arguments.
Descartes further conducts his inquiry into theexistence of God with the supposition that he doubts the principles ofsufficiency and causality. Unfortunately, he uses these principles before he hasproven their validity. To wit: Descartes a posteriori argument for the existenceof God. Descartes believes that God is an infinitely perfect being that couldnot have originated in our minds because an idea such as this would exceed thecausality of the mind, as the mind is less perfect than the content of the ideaitself. Consequently, the idea had to be produced by God himself otherwise therewould be no sufficient reason for the presence of such an idea in the mind.
Clearly, Descartes uses the principles of sufficient reason and causality indemonstrating the existence of God, even though he doubts their validity.Therefore, if he lets these principles stand as doubtful, his entire argument isnullified by doubt. If he accepts them as valid prior to establishing theirvalidity, he is acting in contrary to his fundamental doubt doctrine. In eithercase, he makes the existence of God impossible. Descartes could not prove God’sexistence consistently as he could only do so through the use of a reasoningprocess which, according to his own principles, was essentially doubtful in itsvalidity. The only thing he could ever be certain of was his own existence. Thistoo, strictly speaking, he should have doubted, because he had doubted theprinciple of contradiction and the testimony of his own consciousness.
IfDescartes had been consistent, he would have aligned with the skeptics becausehis universal doubt left him no other choice. Universal doubt, therefore, is aflawed course in pursuing an understanding of human knowledge and the existenceof God. Complete doubt cannot lead to an understanding of human knowledge.Philosophy