Now, I normally wouldn't do this, but the bastards made me read it yet again. Fine, I says, fine – I'll outline Descartes' important arguments in The Meditations for you, gladly. As far as the genesis of this folly goes, Descartes explicitly states his goal in preparing the meditations in the first paragraph of the first meditation:
Some years ago I was struck by the large number of falsehoods that I had accepted as true in my childhood, and by the highly doubtful nature of the whole edifice that I had subsequently based on them. I realized that it was necessary, once in the course of my life, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last.
Descartes throws down the gauntlet
, announcing his intent (to demolish his beliefs, in order to rebuild them) and implies two principles, making his first mistake. True belief, for Descartes, must be certain. Now this, in and of itself, is not a mistake… yet. Because if any of the other following premises in this very long deductive argument of his are false, then this certainty is ruined, along with his whole system. Descartes’ second mistake is his foundationalism
– not only must his belief be certain
, but this certainly must be based upon unimpeachable claims. Descartes will remark shortly thereafter that all knowledge he has “acquired either from the senses or through the senses”, and that the senses sometimes deceive.
Descartes realizes the paradox presented by these contrary claims (namely, one cannot have a certain foundation based solely upon data that is sometimes flawed) and begins his project to find a rationalist basis for his beliefs in order to justify his sometimes empiricism. But when seriously analyzed, these beliefs provoke a serious paradox – even if Descartes is able to reach a non-sensory origination and foundation of knowledge through thought experiments, the methods which he used were acquired through the use of the senses and are therefore flawed. Barring newborns, absolutely no humans can conceive of the world without prior prejudice from their senses, so even though the mechanism or argument that Descartes uses may seem to be purely mentally deductive, his thought patterns themselves were influenced by previous sensory experience. It is impossible to “step outside of ourselves” long enough to construct a reality with pure reason. This may seem to end his project (and I think it does), but he makes many more mistakes that I will be glad to share.
Descartes, having not heard my criticism, proceeds to attempt to offer skeptical arguments in order to strip down the layers of potentially tainted knowledge so that he is left with undoubtable truth. His first attempt is alluded to above; Descartes presents reasons to distrust his senses. This observation is enough to begin the meditations, but is not enough to continue them. Although Descartes’ senses may sometimes deceive him, most of the time they are accurate, leaving him far short of the Universal Doubt he must achieve in order to build his foundation. Descartes’ second skeptical argument is that he may be dreaming, or hallucinating. This is pretty good, eh? Everything in a dream can be questioned, putting all of his beliefs about the world at risk. Except… where do our dream ideas come from? Our sleeping memories of our waking life. So our dreams too are based upon our senses. This troubling detail means that our dream world may not be enough of a stretch to doubt down to our foundation. Descartes then elucidates his final skeptical argument: What if we are in a dreamlike world, have been in this dreamlike world our entire lives; and that instead of this world being a reflection of our sensory data, we have been fed all of the information we believe to be sensory by an evil genius, bent on manipulating us. This evil genius is a dastardly fellow -- all powerful, all knowing, and bent on one thing: lying to us.
This, Descartes says, is his final (and successful) argument. This allows him to doubt everything that he knows with his senses, or so he claims. Descartes then concludes that there are two things that he cannot doubt: he thinks, and he exists. This is Descartes third mistake. Come on, René, can’t you think of anything stronger than that? I can: what if I am merely a computer program, functioning off of input, giving off output, with no independent thought whatsoever – but part of my input is that I have been given independent thought, so I believe this to be the case even though it is not. It is not fair to dear René to phrase things in such a way, being so far removed in centuries. Perhaps, though, I am a creature known as a homunculus – created by a wizard to be a shadow of him/her, believing myself to my own thinking creature, when all of my thoughts are guided by his/hers. In fact, it is far easier to reach a hypothetical situation that involves me not thinking than it is to reach one in which I cease to exist completely (although I do believe that this is possible as well).
This observation dovetails nicely with Descartes’ fourth mistake, mind-body dualism and res cogitans. If Descartes can think, and he exists, and that is all that he can know for sure, then he is a “thinking thing”. We might suppose naturally that we are our bodies, but Descartes believes that he has shown that we could be deceived about our bodies. It could be that we are mere brains in vats, being manipulated by a diabolical genius, and we would not have bodies. Therefore two things: one, our bodies and our minds are two different things; two, our minds are more important than our bodies. We are not merely “thinking things”; we are primarily “thinking things”. Since I am feeling charitable, we shall classify both of these mistakes as one, as they stem from the same source.
Descartes final mistake that we consider here is actually three different mistakes: his three arguments for the existence of God. Descartes argument in Meditation Three is usually considered singular, as a very long ontological argument for the existence of God, following the ghost of St. Anselm. In actuality, Descartes considers three arguments, each increasing in supposed validity, but all are flawed.
Descartes’ first argument for God’s existence is almost all St. Anselm:
P1. I have an idea of an infinitely perfect being.
P2. As a finite creature, I could not have invented this being.
C1. Therefore, this being necessarily exists.
There are easy objections to this argument, which Descartes must have realized, as he answered many of the extant ones in his fuller argument (below).
Descartes second argument for God’s existence is one from the idea of existence itself. It is most often told to me by sneering fundamentalists “Well, if you don’t believe in God, then how did we get here?” While I usually respond to this argument with profanity and dismissal, I shall be more polite with Descartes. What is amusing about this argument is that Descartes must convince himself that he is not God:
P1. I exist.
P2. I cannot have arisen out of nothing.
P3. I am not a perfect being (and thus not God)
P4. I either come from God or a less perfect being.
P5. All less than perfect beings must come from a more perfect being.
C1. All of these roads lead back to God, therefore God exists.
P2 is of course most problematic here (P5 is rather obviously wrong as well) , and I leave it to the natural sciences to answer that particular question.
Descartes’ last argument for God’s existence is the argument from ideas. Descartes outlines three ways that he might know things: ideas may be adventitious1, innate, and invented by him. He also claims that he clearly and distinctly perceives the existence of God. Therefore, God exists. To be completely fair to Descartes, this is my best approximation of his fullest argument:
P1. There are three sources of ideas: Empirical, Innate, Invented.
P2. I have an idea of an infinitely perfect being.
P3. This idea was not acquired empirically.
P4. This being is greater than myself, and therefore could not have been invented by me.
C1. This idea must, therefore, be innate.
P5. Only a perfect being itself is great enough to infuse me with an idea this great.
C2. Therefore, there must be a being that did so.
The logic of this proof seems simple, and true enough. One of the problems of the deductive format of argumentation is that it can make unreasonable arguments appear quite reasonable. Needless to say, here his premises are the real flaws. P1 is flawed in a number of ways – anyone who has dealt with children realizes there are no such things as innate ideas that extend past crying or sucking on a nipple
; and if one views the mind as a sort of sensory instrument, ideas cannot be invented, merely discovered. P2 would seem to be contradicted by P4 and P5 – if we cannot think about a perfect being well enough to invent him, then how can we have a clear and distinct idea of him (remember, this is not just an idea of God, it is an idea so clear and distinct that the idea itself necessitates his existence).
It could be said that Descartes creates another mistake when insisting that God is necessary for his project, but this is just his first two mistakes revisited. Descartes insistence upon certainty (upon which to build his foundation for true knowledge) necessitates a way to escape from the possibility of an evil genius. The only artifice he can build is an omnipotent, omniscient, omnibenevolent being (God) that can ensure that his senses or an evil genius are not deceiving him. If he were content to live in a world of partial uncertainty, judging his beliefs by a rubric of varying plausibility and possibility the entire exercise could have been avoided.
1. This is translated in the French version as “foreign to me and coming from the outside”. This information is sense data, and I feel more comfortable using the common term “Empirical” to describe it.