Descartes’ ultimate goal is to set a solid philosophical foundation for science in the hopes of learning to master and control nature. Descartes’ argument in this regard begins with the premise that he exists as a thinking thing (D. 34). Upon the premise he is a thinking being, Descartes seeks next to establish a proof for God’s existence. He asserts the mind is more capable of being known and understood than the body such that ideas are more palpable than what our senses observe. Descartes uses the primacy of ideas over observation so as to prove that God’s existence: Descartes’ knowledge of God is deduced from the innate idea of God within the mind and without God’s existence it would be impossible for Descartes to be certain of anything, especially science or knowledge itself. However, upon assessment, I find Descartes’ proof does not fully account for the degree to which imagination leads the mind to hold erroneous ideas.
Much of the argument Descartes presents is unassailable. Descartes posits that he has a clear and distinct perception of God, and therefore God must exist. Descartes possesses a clear and distinct idea that there exists a perfect being, or God (76). To this end, Descartes states, “The result is that, of all the ideas that are in me, the idea that I have of God is the most true, the most clear and distinct.” Clear and distinct perceptions in the mind are things that are self-evident, and therefore cannot be doubted. For Descartes then, he has the idea that God is a perfect being, He is clear and distinct from all other things, and He is the ultimate creator. Since Descartes clearly and distinctly perceives Him, God exists.
Rather than a broad definition of thought, Descartes divides thought into constituent parts, or categories, that are easier to understand. He classifies thought as volitions, emotions, and judgments (D. 37). While volitions and emotions are always true, judgments concern what is both true and false. Because he has made false judgments in the past, Descartes treats judgment cautiously. Descartes further breaks down ideas occurring in the mind by classifying these as innate, adventitious, or fabricated (D. 38). An adventitious idea is a sensation created in the mind by an external force with its internal content settled. A fabricated idea is created by and exists only within the mind and the mind controls its internal content. An innate idea is immutable and placed in the mind by God and can be examined and even set aside (D. 72).
An idea, according to Descartes, represents a varying amount or part of reality. He says, “Now as far as ideas are concerned, if they are considered alone and in their own right, without being referred to something else, they cannot, properly speaking, be false.” All ideas, regardless of their cause, exist truly as ideas. All ideas represent some degree of objective reality which means that they represent the reality of an idea. This is the concept of being able to hold an idea in our head that does not actually exist. For example, we can picture a unicorn even though they are not real. Other ideas represent a formal reality which is a reality that an actual thing possesses. An example is the idea of a human has objective reality in the way it represents a human, but also has formal reality in that a human exists as an actual thing. Although Descartes separates ideas into various causes, he cannot speak to the cause of an idea without referring also to its substance. The formal reality of a thing is its substance.
The substance of a thing is a physical representation of other attributes. The color brown exists, but one cannot describe brown to another person without pointing out a substance having the attribute of brown. For example, the dog (i.e., a substance), is brown (i.e., an accident). The dog exists in and of itself, while the color brown only exists in relation to a substance, in this example the particular dog. Since the substance exists in actuality without having to relate to some other being, Descartes concludes the substance of an idea is greater than the accident of that idea (D 45). The dichotomy between substance and accident is a crucial step in the proof of God’s existence because Descartes establishes that something cannot come from nothing.
In so much as Descartes exists, he knows something would have to create him because everything requires a cause. Descartes explains, “Hence it follows that something cannot come into being out of nothing, and also that what is more perfect (that is, what contains in itself more reality) cannot come into being from what is less perfect.” Thus, the cause of a thing must be equal to or greater than what it created. So too with ideas. Ideas have to have causes and those causes have to contain as much objective reality as the idea actually represents. Descartes has an idea of a perfect being which he calls God. The idea of God is an effect that must have a source, and the source or cause must also contain at least as much as or more reality than what the idea (i.e., God) represents. In Descartes’ conception the objective reality of God is a perfect, omnipotent, divine being. Therefore, the cause of Descartes’ idea of God as divine reality, must contain as much divinity as his idea of God represents. God as a perfect being would have to be created by something either as perfect or more perfect than the idea of God. Because Descartes acknowledges he is not perfect, it follows that he did not create God. The creator of God has to be infinite and perfect, just as God is. The only being that exists that possesses that possibility is God, therefore God exists.
Ultimately, Descartes proves Gods existence because he has a clear and distinct idea of God. He summarizes his proof at the end of the Mediation when he says, “Indeed I have no choice but to conclude that the mere fact of my existing and of there being in me an idea of a most perfect being, that is God, demonstrates most evidently that God too exists.” Because he has the idea of God, a perfect being, he believes that in order for him to be able to possess that idea, some perfect being would have to have instilled that idea within him. Since he is not perfect, he cannot be the creator of this idea. God is a perfect being and in being perfect nothing can be more whole than God. Therefore, the idea of God was created by God, and Descartes uses this to prove that God exists.
Descartes believes the proof of God is incapable of being doubted. Looking closely at the proof, my assessment concentrates on the inherent “imagination error” within “fabricated ideas”, and why such an error is a reasonable basis upon which to question whether this proof is sufficient. Descartes’ description of the relationship between the cause of a thing and the thing created does not foreclose the possibility that the cause of a thing is imagined by the perceiving being (i.e., by Descartes’ “I”).
Descartes states plainly, “The whole force of the argument rests on the fact that I recognize that it would be impossible for me to exist, being of such a nature as I am (namely, having in me the idea of God), unless God did in fact exist.” His entire proof of God’s existence rests on the postulate that he can “clearly and distinctly” perceive God through his reason (D. 70). This is all based upon his conception that the cause of an idea must have at least as much objective reality as the idea represents. As set forth above, Descartes asserts, “something cannot come into being out of nothing.” From this assertion, it follows that an entity in being (i.e., having existence) has awareness. But, in this regard, it is not clear that what Descartes perceives is at least on par with what Descartes can imagine. If a thing imagined is only potential, and not a thing in and of itself, then imagined things are nothing. But it does not follow that Descartes does not imagine. Rather, imagination exists and things imagined have an existence of some order. Thus, a distinction between what is perceived and what is imagined becomes tenuous: an entity in being can think about, or imagine, the absence of existence, or the absence of awareness for that matter. By the imagining of non-existence, then the concept of non-existence must exist.
This conclusion means either existence and awareness are not strictly co-extant, or that an “imagination error” (a deception about existence or awareness) exists along with existence and awareness. The error referred to here is the fact that the perceiving being (i.e., Descartes’ “I”) may not actually be imagining non-existence but merely a hypothetical premise that an opposite reality can exist. An example of this imagination error might be described as where I perceive brown, while I can also imagine the non-existence of brown, with the attendant question of whether I merely fabricating the belief that the non-existence of brown is a reality opposed to merely a hypothesis. While there is greater strength to the thing perceived (i.e., brown) as compared with the imagination of the non-existence of the thing (i.e., non-brown), that strength is not absolute.