Radical Doubt

I often get a little obsessed with things I read, especially when it’s related to philosophy. For awhile now I have been thinking a lot about Descartes’ Method of Radical Doubt and I haven’t been able to get it out of my head.

The Method of Radical Doubt is a process where a person doubts their own beliefs to test whether those beliefs are actually true. It’s a means of defeating skepticism on it own ground. I was drawn to the idea because I tend to be the type of person who doubts everything unless shown absolute proof or I’m presented with well thought out logic behind an argument.

I like to audit my own beliefs every so often to just make sure I haven’t fallen into the trap of blindly following another’s beliefs or prejudices.

The first rule was never to accept anything as true unless I recognized it to be evidently such: that is, carefully to avoid precipitation and prejudgment, and to include nothing in my conclusions unless it presented itself so clearly and distinctly to my mind that there was no occasion to doubt it.

– René Descartes, “Discourse on the Method of Rightly Conducting the Reason and Seeking Truth in the Field of Science”; translated by Laurence J. Lafl

Descartes himself tried to establish doubt in three areas:

The first is Perceptual Illusion. What if everything we perceive is wrong? The idea that I cannot trust my own senses is a hard pill to swallow, but an interesting one none the less. How can we be sure that we are seeing, or hearing, or feeling, things as they really are. Descartes argues that it is wise to, at least at first, doubt every bit of sensory knowledge we take in until we can be sure that our perceptions are correct. Remember, things may not always be as they seem.

The next is the Dream Problem. This is the one that really messed with my head! The Dream Problem is related to the Perceptual Illusion in that, if my own dreams feel real, how can I be sure that the world I am experiencing (perceiving, sensing) is real. How do I know that everything around me isn’t just a fabrication of my own imagination?

It’s sort of like the movie “The Matrix”. Every one could be hooked up to a machine that is stimulating your brain in such a way as to make you think you are in a real world. The brain is where all of our perceptions come from, right? So it would be possible to get a person to see, taste, hear, feel, or smell something that isn’t really there. I do believe that I am really doing the things I am doing and that the world around me is real, but thinking about this problem has made me realize that I can’t actually prove that belief to be true. Freaky!

Lastly, the Deceiving God. Descartes raises more doubts by asking us to entertain a radical belief different from one of our own treasured beliefs. The example given is a religious one and because I am not religious it was hard for me to understand at first. What if there is an omnipotent god, but that deity devotes its full attention to deceiving me?

He doesn’t mean that God would force me to believe something that was false, which I find a more interesting prospect, but that anytime I think I believe something for sure, God could choose to change the world in such a way that my belief becomes false. He seems to suggest that even if we could distinguish dream from reality we could experience reality as if it were a dream. If that is true then it is possible to doubt everything you come to believe.

Descartes did offer alternative versions for those religious devout who couldn’t stomach the idea that God would do such a thing. One was that there is a sort of demon who relentlessly tortures you with your own error, or, and more interesting, I actually deceive myself. The latter is interesting because I believe that our own mind’s often work against us in was we can’t perceive and I imagine it is possible for your own brain to deceive you.

In the alternatives the point is still the same, that it is possible for every belief you hold to be false.

After reading all that it might seem like nothing can ever be thought to be true and you might be ready to panic but Descartes was able to assert one fact, one truth, though all of this doubting. He concluded that the very act of doubting, and thinking about doubt, meant he was a thinking thing, and if he was a thing, that meant that he existed.

Cogito ergo sum, I think, therefore I am.

So whenever I get weirded out by these thoughts that every thing I think I know about the world, and about myself, might be nothing but a dream or clever deception, I hold on to the one thing I know to be true.

I know that I am real.


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Hello! My name is Lisa. I find the human condition fascinating and I often write stuff about that. I blog at zenandpi.com but you can also find me on Twitter, Tumblr, and Instagram, and if you like what I do, consider signing up for my newsletter. Thanks :)

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