In Rene Descartes Meditations on First Philosophy, Descartes is seeking to find a system of stable, lasting and certain knowledge, which he can ultimately regard as the Truth. In his methodical quest to carry out his task, Descartes eventually arrives at the proverbial fork in the road: how to bridge the knowledge of self with that of the rest of the world. Descartesa answer to this is to prove the existence of God.
The purpose of this essay will be to state and explain Descartes’ Third Meditation: Proof of God’s Existence by identifying relevant concepts and terminology and their relationship to each other and examining each premise as well as the conclusion of the proof and finally to comment on the significance of the proof in the context of the Evil Genius assumption. In order to begin explaining the meaning and significance of Descartes’ Third Meditation Proof of God’s Existence, I feel that it is very important to define the terms and concepts that he uses in the meditation and the terms and concepts that I will be using throughout the paper.
The first of these concepts deals with kinds of reality. By this I am concerned with reality’s relationship to the mind. The two kinds of reality introduced are subjective and formal. Subjective reality involves those things which are mind dependent, more commonly thought of as ideas. It is an object which possesses both discernible and tangible characteristics capable of being verified by all those who observe it, even without previous knowledge of such objects.
It should also be noted that objects of formal reality are generally the cause of objects of subjective reality. The second concept I will examine in order to fully appreciate Descartes’ Third Meditation Proof of God’s Existence concerns Degrees of Reality. By this I mean a ranking of the representative qualities of either kind of reality. The lowest degree of reality deals with accidents and modifications, things which are characteristics or expressions of objects with a higher degree of reality.
An example of this would be the individual holes and marks on the classroom ceiling. These characteristics cannot exists by themselves and are thus subject to the existence of things in the next highest degree of reality, that of substances. Substances are finite objects or ideas with conceivable limits. In the previous example, the ceiling itself is the substance with the holes and markings (of a lower degree of reality) being dependent upon it for their continued existence. The highest degree of reality involves the infinite.
The infinite represents substances that are unbounded and possess no conceivable or tangible limits in any of their aspects or qualities. The only example of this for Descartes would be an entity of omnipotence, who would be all knowing, all powerful, and that of which no greater can be conceived, in other words God. The next concept that must be explained is in fact the very first premise for Descartes’ Third Meditation Proof for the Existence of God, that of the Causal Adequacy Principle.
Descartes reasons that “as the idea contains one particular subjective reality rather than another, it must get this reality from a cause having at least as much formal reality as the idea has subjective reality” (p 58). In this, Descartes attempts to tie together the concepts on kinds of reality and degrees of reality. Returning to the example using the ceiling, Descartes would argue that the thing causing or bringing into existence the idea of the ceiling (a mind dependent entity) could only be another finite substance (i. e. the actual ceiling) or an infinite substance (i. e. God), either of which would be of formal (mind independent) reality.
In saying this I eliminate the notion that the idea of the ceiling could be sustained by the holes and markings (accidents and modifications) because according to Descartes they are of a lower degree of reality, and what is of lower degree cannot of itself bring about something of a higher degree. The second premise of Descartes Third Meditation Proof of God’s Existence stems from introspection, that is, Descartes direct mental inspection his thoughts as a thinking thing. In this Descartes recounts what he knows to be true up to this point.
He concludes that what little things he knows such as substance, duration , number, and extension, shape , place, and motion are no greater than himself and indeed may be in him eminently. He considers these things to be as finite as he is. But now, I introduce a further revelation of Descartes mind, that of his conception or idea of an infinite substance. In this he means a substance that is “independent, supremely intelligent and supremely powerful” (p. 60). Moreover, a substance which extends beyond the bounds of his minds and in whom lies the limitless concepts of both things that he can and cannot perceive.
At this point I should call attention to the significance of Descartes’ thinking. One of the qualities Descartes assumes about himself is that his power of conception is far greater than the power of his imagination. Thus he conceive of a great many objects and ideas such as the chiliagon (a thousand sided figure) that he will forever remain hopeless to be able to grasp a mental image of. The second point that should be brought to light is the inherent concept of understanding the of the infinite before you can grasp the finite.
To this Descartes thinks in terms of the infinite as the absence of limits in the same way that he thinks of rest as the absence of motion and light as the absence of darkness (p. 60). The specific relevance of this point to Descartes’ proof will be discussed in the next section The logical conclusion of Descartes Third Meditation for God’s existence is that in fact an infinite substance (i. e. God) must exists: “I who am finite would not have the idea of an infinite substance in me unless it came from a substance that really was infinite (p. ).
Descartes knows that cannot have been the cause of such a substance because he himself is of a lower degree of reality than God. Thus to Descartes this infinite substance would have all the conceivable qualities Descartes can ascribe to an infinite degree. Moreover, in returning to the point about the concept of the infinite before the finite, Descartes speculates that his concept of an infinitely perfect God must be prior knowledge to his still as yet limited understanding of his flawed and imperfect self.
This proof of God’s Existence discount the earlier possible existence of an Evil Genius. Because Descartes has shown God to be an infinite substance clearly not of his own minds’ creation, but in fact a limitless being with infinite powers including those of power and goodness. This first quality alone is enough to dismiss the Evil Genius for there can only be room enough for one all powerful being and if in fact God is that being than that leaves no room for another.
Furthermore, since God possesses infinite goodness it would seem contrary to his nature to engage us in a continual deception based on either our apriori or aposteriori beliefs. In conclusion, Descartes’ Third Meditation Proof of God’s Existence represents a critical step in Descartes overall goal of obtaining a system of certain, lasting, and stable knowledge: that of using the existence of God to bridge the gap between knowledge of self and knowledge of the external world.
In building this bridge I must first define the different kinds and degrees of reality and how they relate to one another. From this we are able to see the logic behind Descartes Causal Adequacy Principle, follow his second premise, and reach the same inevitable conclusion that Descartes does: that an infinite unbounded substance through which all conceivable qualities without end (i. e. God) must exists. For Descartes’ this will lay the very foundation for him to expand beyond his limited thinking mind and begin to explore the very depths of the universe in his quest to find the Truth.
