The Effect Of René Descartes Meditations On First Philosophy

Philosophers have used two main methods as a means of proving this; either a priori or a posteriori. A priori reasoning or knowledge can be achieved without any experience or knowledge from the outside world. The ideas are said to be innate or we already have a notion of knowledge when we are born. This is the method René Descartes uses in his arguments in his work Meditations on First Philosophy. Descartes uses a priori to its strengths and weaknesses. In my opinion a priori reasoning has its weaknesses in its strengths and therefore cannot convince the modern day reader of a plausible approach to proving Gods existence. The other method, a posteriori reasoning, gives us a backbone for a priori reasoning and both play off one another. A posteriori
reasoning justifies knowledge on the dependency of experience or empirical evidence. Empirical evidence can be acquired through observation or experimentation. Empiricists David Hume might explain this evidence as cause and effect in his work An Enquiry Concerning Human Understanding. Hume also puts restrictions on our knowledge and states that we cannot have a proof of God’s physical and actual existence, but rather knowledge of the ideas of God that we perceive. Both a priori and a posteriori reasoning, exhibited by Descartes and Hume, have failed to give believable proof of the existence of God.
Descartes ideas are logical and easy to follow yet his arguments run in a circular fashion where he makes many assumptions and this is the downfall to a priori reasoning.
The logical format is illustrated when Descartes refers to the ideas of innateness and certain ideas being defined as clear and distinct perceptions. Using this organization he portrays his argument by stating that God is innate just as mathematics is innate. (Descartes, 59A) Using Descartes’ assumption that God has planted everything in our mind, and just as we know that 2+2 is equal to 4 and 4 exists because of 2+2, and this idea is instinctive, he then justifies God in the same innate sense. This is what Descartes would call a necessary truth; in fact, the laws of geometry and arithmetic are all necessary truths. These necessary truths incur no falsity and are clear and distinct perceptions to us. God’s existence is therefore necessary because of a clear and distinct idea of a supreme being. Not only do we acknowledge God as existent, but unlike other innate ideas, the idea of God cannot have come from our own (human) thoughts. Rather, it was planted into our minds by God himself. The logicality of Descartes’ proof of God is easy to follow and it is easy for one to understand an innate idea, but within these strengths lay the weaknesses of a priori
reasoning.
This proof of God however is the circular argument previously mentioned.
Descartes uses the premise to prove the proposition and then uses the proposition to prove the premise. So Descartes states that you use your clear and distinct ideas to prove God, whilst also requiring God (the proposition here) to prove your clear and distinct ideas which is a circular argument; the Cartesian Circle. Descartes makes many inferences and assumptions in his proof of Gods existence and this causes the holes in his argument. Not only does the circular fashion cause holes, but one’s own perception of the world may interfere with this idea of innateness. If God is innate and God has implanted himself in our innateness, then how can one explain an
atheist? Again, within these logical steps Descartes lays out are the circular ideas which are based on assumptions. First we see Descartes state,
“But though, in truth, I cannot conceive a God unless as existing, any more than I can a mountain without a valley, yet, just as it does not follow that there is any mountain in the world merely because I conceive a mountain with a valley, so likewise, though I conceive God as existing, it does not seem to follow on that account that God exists.”
Descartes gives a good argument for why God cannot exist, but then he turns back to the argument and says he does exist;
“Because I cannot conceive a mountain without a valley, it does not follow that there is any mountain or valley in existence, but simply that the mountain or valley, whether they do or do not exist, are inseparable from each other; whereas, on the other hand, because I cannot conceive God unless as existing, it follows that existence is inseparable from him, and therefore that he really exists:” (Descartes, 59B)
Descartes’ a priori reasoning is his strength, but within this lays his assumptions and circular argument which are his weaknesses. Descartes’ does not give a convincing reason to prove in the existence of God. The deductive reasoning of a priori argument can be constructive and destructive to a philosopher’s argument, in this case Descartes. The simple idea of one being able to understand God is enough to prove that God exists may be an understandable and logical argument, but in this lays the many assumptions that can be made in a priori reasoning. Descartes’ infamous line is "I think therefore I am." Descartes assumes that logic and reason, the tools used to make sense of the "I think therefore I am" argument, is the correct explanation. Descartes assumes that his thoughts must be correct thoughts because he thought them up and they appear to be correct to him. This cannot define a human as existing solely on the reliance of our own thoughts. How do we know for sure that our very existence and our thoughts are actually connected? We cannot simply state that this is right because it makes sense. Descartes rests his proof on the doctrine of clear and distinct ideas, and the claim that whatever can be clearly and distinctly conceived shows us the truth, but this, to me, is not convincing enough. Hume’s distinctions do not give us any more of a clear proof of an existence for a God. Hume states that we simply form the idea of God as he is represented to us. We go to church and we are given the idea of God, but we have no proof of whether or not he arose from something that actually existed. Our knowledge cannot be extended outside the relationship between the ideas we assume upon experience, like church or religion. God is an idea and has not been proven to be of a physical matter and therefor is not what Hume calls a matter of fact but must be a form of relations of ideas. Stating that God exists is just a relation of ideas we have formed in our minds.
Digging deeper into Hume’s work, we can investigate his reasoning through an idea called “Hume’s Fork.” “All the objects of human reason or enquiry may naturally be divided into two kinds, to wit, Relations of Ideas, and Matters of fact. Of the first kind are the sciences of Geometry, Algebra, and Arithmetic ... [which are] discoverable by the mere operation of thought ... Matters of fact, which are the second object of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing.” Hume’s ideas are divided into two parts; relations of ideas (a priori) and matters of fact (a posteriori). Relations of ideas are true by definition and the negations are contradictory. These can be known by reason alone and have no need for observation. Matters of fact are concerned with the existence of things and rely upon sense experience. So here is the distinction Hume lays out for a priori reasoning and a posteriori reasoning giving us two ways of achieving knowledge, however, attempting to achieve knowledge trough human reasoning requires matters of fact, but matter of fact can only be known based on sense experience. Hume continues by defining the cause-and-effect relationship. The example is that a stone is let go and the stone then falls. We can agree that the stone will always fall when let go; this cannot predict what will happen in the future logically though. This can only tell us about the past and past experiences. The circumstances may be changing and thus we cannot rely upon the future to conform to the same principles that were governed during past experiences. Causality is then based on experience and is not known a priori, but a posteriori. Yet all the experience can establish is that the cause (the stone being let go) is prior in time to and contiguous with its effect (the stone falling). So a posteriori reasoning cannot tell us that the cause can produce the effect, but we just assume this because our mind has seen that the effect (the stone falling) usually follows the cause (the stone being let go) and we have never seen it occur otherwise.