The Generalist

Descartes’ Proof that God Exists

Recently I wrote a post called Pondering the Universe in which I laid out some ideas regarding consciousness and metaphysics that I have been examining. In that post, I mention Descartes’ views about the nature of consciousness or the ‘soul’. To get a better idea of exactly what his views are on this topic, I decided to read for myself René Descartes’ Discourse on Method and Meditations on First Philosophy. I am very much enjoying my reading, but it is by no means easy. If you are interested in picking up a copy, make sure you get a good translation. I recommend Donald A. Cress’ translation, which you can buy following the above link.

I have only finished reading Discourse on Method and still have Meditations to go. Nevertheless, I’m going to throw my ideas out there in the hope that I can start up some conversation. By all means comment with your thoughts.

Here, so far, are my understanding of one of Descartes’ most famous proofs – the proof that God exists.

  1. I think, therefore I exist
  2. I doubt, therefore I am not perfect
  3. That I am not perfect implies the existence of something that is perfect upon which I depend – i.e., God

That’s the proof in a nutshell. It is really quite elegant, but I think rather misunderstood. The problem isn’t the proof, but rather the use of the term “God”.

The term “God” is an equivocation. It has so many connotations packaged into it that it is all but useless for communication today. Two people discussing “God” may have such entirely different ideas about what they are talking about in the first place that agreement on anything related is utterly impossible. Today, any philosophical use of the word is shunned because it implies a religious viewpoint (i.e., a viewpoint based on faith rather than on reason). At the time when Descartes was writing his philosophy, the religious environment was even more strongly charged. The Roman Catholic Church was particularly powerful and defying it could cost you your life. To make the proof easier for modern readers to understand it is probably worth it to replace the word God with “truth” or “external reality” or simply “another being”. The point is really that something other than me exists and my own existence is dependent on that thing. So we can rewrite the proof thus:

  1. I think, therefore I exist
  2. I doubt, therefore I am not perfect.
  3. That I am not perfect implies the existence of something external to me upon which my existence depends

Breaking this proof down a little bit in order to understand it better:

1. I think, therefore I exist

This is pretty straightforward and even Descartes remarks that he has never had any problems with anyone arguing otherwise.

2. I doubt, therefore I am not perfect.

Now, here there can be some issues. What exactly does Descartes mean by “perfect”? We can avoid that, I think, by saying something like this:

2. I doubt, therefore there is something I do not know.

To make this a little clearer realize that the act of doubting itself is an admission that one does not know something, if only that he does not know that he knows!

3. That there is something I do not know implies there exists something external to me upon which my existence depends

Descartes argues that in order for me to have a concept of something that I do not know, there must indeed exist something to be known, i.e., there must be something besides me in existence. If I were in fact the only being, I would have no means of obtaining such a concept from myself because as the only thing in existence I would, by necessity, be all-knowing.

Now because there is something to know and I do not know it, there must exist something else, but what’s more, this other thing must necessarily be superior to me, i.e., it must be something upon which my existence depends. Why is this necessarily so? Because if I were in fact superior to this other being, I would not lack what it represents.

Descartes seems to be saying also that all things of which I have can have any clear idea (a clear idea is anything non-contradictory) but that I am unable to produce for myself are ideas that I must have received from an entity other than myself and they must therefore exist in that entity. (Keep in mind that Descartes’ idea of God is not all-powerful in the sense that he cannot contradict himself – i.e., he cannot “create a rock too heavy for him to lift”.)

Think about that a bit if you’re not seeing it right away. Remember that Descartes starting point is I think therefore I exist and realize that this is the only axiom at this point.

Now, I am still in the process of reading and parsing this stuff, so I may revise this as time goes on. I will post my thoughts as they come to me so check the comments section for pingbacks. In the meantime, I do hope to see some discussion.


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