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1. Explain as fully as you can the function of Descartes’ method of doubt.

To build any sort of rigorous body of knowledge, in any field be it mathematics, philosophy, or other, one must start with absolutely nothing. That is, they must begin their quest for knowledge with no preconceived ideas of the mechanics of objects and no previously known facts taken to be true. This is because the only way to be fully sure of a body of knowledge is to examine every single line of logic and every assumption that led to the creation of that body of knowledge with absolutely unyielding scrutiny. Whether we have any justification for such scrutiny, such as the realization that knowledge obtained directly or through deductions from sensory information can be misleading, is for the most part immaterial. In any instance, meditators are surely to have accepted and built off of knowledge in their repertoire that was not subjected to this high degree of scrutiny. It is Descartes’ method of doubt which functions to clean this slate for the meditator. Descartes provides reasons for why the all-encompassing doubt is warranted, but a truly motivated meditator would immediately understand why such doubt is necessary. 

From this empty expanse of knowledge, Descartes hopes to find kernels of truth, which he trusts will be undeniable even when faced with the full force of the scrutiny that wiped away all of the meditator’s prior knowledge. Descartes is, in effect, trying to identify an axiom or axioms on which to build a new, or perhaps identical, but surely sound, body of knowledge. Thus, Descartes’ method of doubt also functions to allow for this identification to occur, as axioms are foundational (as well as independent, as surely noted after Euclid’s fifth postulate fiasco) and therefore must be identified in the absence of other ideas that are taken to be true.  

Moreover, Descartes’ method of doubt also functions to ensure all meditators start in the same state, so long as they follow the first meditation as instructed. This is ideal because if Descartes controls all subsequently proposed axioms and deductions (which he does), then, so long as the meditator correctly follows the instructions in every meditation, Descartes may argue that there is no reason any meditator’s end conclusions should differ from his own, provided Descartes’ logic is sound and the meditator agrees with this logic. 

2. In M2, Descartes describes a sense in which the cogito is certain and necessarily true. But near the beginning of M3, he states that everything is subject to the M1 defective nature doubt. Explain how to resolve this apparent conflict.

Throughout the meditations, and with increased frequency in Meditation 3, there is a very subtle distinction that Descartes alludes to that, when identified, can act as a resolve for this “Cartesian circle”. And while Descartes does not explicitly state this distinction in the body of the meditations, it is implicit that there exists a larger degree of certainty for a small number of the statements that Descartes claims to be clear and distinct. The first in this set of more certain clear and distinct statements is his “cogito ergo sum”. This axiom, according to Descartes, is so self-evident that it is utterly immune to doubt, to the degree that it may be argued that this includes immunity to defective nature doubt. An easy mistake is to focus on the misquoting of Descartes’ famous first result which employes the word “ergo”, which indicates an inference and thus begs subjection to defective nature doubt (as it is possible that an ultimate deceiver has inherently flawed the deductive abilities of the meditator), but Descartes carefully shows that he may spontaneously exclaim “I am, I exist” in Meditation 1 without employing any use of syllogism. Descartes’ exclamation is made possible by the inseparable nature of thinking and existing (existing as a thinking thing), and thus he is able to use this as a true axiom, as a deceiver will “never bring it about that [he is] nothing”. Similarly, although perhaps with less confidence, Descartes is able to claim that the idea of God is indubitable and thus is also not subject to defective nature doubt. 

With these two certainties secured, Descartes is able to proceed into his proof of the omni-benevolence of God with solid axioms (rather than, as it may have appeared, postulates whose truth in fact relies on God’s benevolence). Given now that Descartes is able to enter into his benevolent God proof with non-contingent axioms, he is able to soundly show God’s benevolence and thereby that all of the meditator’s other, in some sense lesser, clear and distinct perceptions which were susceptible to defective nature doubt (such as 2+3=5) are in fact true. 

In essence, this conflict arises because of the absence of explicit terminology for different levels of certainty in the clear and distinct perceptions that Descartes encounters through the meditations. It should be understood that “cogito ergo sum”, or more accurately put, “cogito” and “sum” (as they are really meant to be simultaneous), and the other clear and distinct perceptions that Descartes uses in order to prove the benevolence of God are not subject to the doubt that this benevolence is used to dissolve (namely, defective nature doubt). Once this is understood, it becomes apparent that no such conflict between Meditation 1 and 3 exists. 

3. Part of the project of M4 is to provide a theodicy for falsity and error in thinking things. Explain why this aspect of M4 needs to be paralleled in M6 and explain some of the similarities or parallels. 

Descartes needs to apply a similar explanation for error in Meditation 6 as he did in Meditation 4 because he has shown that God is responsible for instilling within humans their nature. This leads to a concern in Meditation 6 because if God is responsible for the nature of human beings, and human beings are sometimes driven by their nature to harm (such as the instance when one feels compelled by her nature to eat or drink while bearing an illness that renders the ingestion of food or drink harmful), then this would imply that God has instilled in human beings a somehow defective, imperfect nature. This is a parallel concern in Meditation 4, as Meditation 4 was partly concerned with why it was possible for a meditator’s judgements to be on occasion false, as this seems to contradict God’s benevolence, considering the fact that the meditator was certainly created by God. 

A strong similarity between the Meditation 4 defense and the Meditation 6 defense is that they essentially offer an identical explanation: human beings are limited in some way, and this limited state that does not contradict God’s benevolence. Essentially, it is reasoned that a meditator is capable of error because God made her will infinite, but her intellect finite (and the only way she is actually able to commit an error is to apply her will beyond the bounds of her intellect). Similarly, the meditator’s shortcoming which allow for a desire to drink poisoned water is due to a physical limitation (her body’s Pineal gland, responsible for all inter body-mind communication, actually has limited means by which to communicate to her mind), and thus is not able to fully inform the mind of the dangers of the poison. Moreover, in both of these instances, the defense for why God did not create human beings in such a way that they did not err or were endowed with special mental abilities in order to detect elusive dangers such as poisoned water is because this change would have resulted in some less than ideal world (that is, God optimizes globally, not locally).

Another similarity is a sort of duality that exists in both Meditation 4 and Meditation 6. In Meditation 4, Descartes explains a simultaneously existing and acting will and intellect. In Meditation 6, the attention turns to a duality of mind and body. In both, there exists one component which was made to be perfect and whole by God (that is, the will in Meditation 4 which is in fact said to be as full and complete as God’s, and the mind in Meditation 6), and one component which is in a sense incomplete or lacking (the intellect in Meditation 4 and the body in Meditation 6). It is thus, in both Meditation 4 and Meditation 6, this incomplete or lacking component that is ultimately responsible for the errors (indirectly in the case of the intellect, as this is only when the meditator applies her will in making a judgement where her intellect is not matching). 

4. Why does Descartes need to reconsider God’s existence in M5? What are the important similarities and differences between the M3 and M5 proofs? 

Descartes reconsiders God’s existence in Meditation 5, with no real need or desperation  (perhaps only to assure the meditator that such proofs really are possible, demonstrating that he is able to show multiple), mainly because when considering a proof of the properties of triangles by using clear and distinct attributes, he realizes the foundational truths that he has setup in the prior meditations also allow for an entirely alternative proof of God. 

In Meditation 5, Descartes concludes that his idea of a triangle must hold all of the attributes that he believes a triangle must have because he is able to clearly and distinctly perceive these attributes. Analogously, Descartes says that the idea of God exists in his mind, and that he clearly and distinctly perceives many attributes of God, one of which being that God exists, and therefore God must exist just as, for instance, an ideal triangle must have 3 sides. With this, Descartes is able to show that God must exist at least with as much certainty as fundamental mathematical truths which are clear and distinct. This is a very fundamental difference between the Meditation 3 proof and the Meditation 5 proof, as the proof of God in Meditation 3 claimed to prove God’s existence with unconditional certainty (using only irrefutable axioms as the basis for a derivation), while in Meditation 5, Descartes’ proof only shows God’s existence to be as sure as foundational mathematical truths, such as 2+3=5. 

Another important difference between the proofs is that the Meditation 3 proof relies on a central postulate, which is that the idea of something infinite (that is, the idea of God) could not have come from something finite (for instance, from a meditator’s parents). This contrasts with the Meditation 5 proof which only relies on clear and distinct perceptions which Descartes claims are so self-evident that they are irrefutable by any measure. 

A similarity between the Meditation 3 and Meditation 5 proof of God is that they both rely centrally on the meditator having some idea of God.

Although perfection and infinity are often conflated in the Meditations, another possible difference between the two proofs is that in the Meditation 3 proof, the axioms by which the existence of God is proven only necessitate that the idea of God be infinite, while the proof made in Meditation 5 also relies on the meditator’s clear and distinct idea of God including God’s attribute of perfection (and therefore, according to Descartes, the attribute of existence).  

Finally, another subtle difference between the two proofs is that one relies on clearly and distinctly perceiving the idea of God and the other relies on clearly and distinctly perceiving an attribute of God. That is, in Meditation 5, the meditator must clearly and distinctly perceive the existence attribute of God, while in Meditation 3 the meditator must clearly and distinctly perceive the idea of God.