Posted by In Vino on October 09, 19103 at 19:29:47:
In Reply to: Re: What can be called into doubt posted by PG on October 08, 19103 at 18:20:00:
: According to Descartes, empiricism must be
: wrong because we are justified in doubting whatever we believe based on
: our senses. Why? Because we often make mistakes about such beliefs
: based on the senses. We find out later that what we believed was wrong.
: But how can we know anything we are justified in doubting? We cannot.
The major problem of Descartes' thinking is, unfortunately, his starting point. That is to say, he begins in all things with Doubt. Doubt is a slave to "what ifs" and fanciful imaginings and inherently undermines the very idea of truth or knowledge. Systematic doubt and knowledge cannot coexist because one can always doubt, even without reason (more on this later). Plato's idea of knowledge was that of Justified True Belief. Without getting into a whole discussion here, I will just say that it is a helpful contrast to Descartes. Descartes starts with doubt, Plato starts with belief. Both maintain that they must be rational (of course, neither completely succeeds - but that's a different topic). By beginning with belief, we see that our senses can sometimes certainly be fooled, but that they are generally reliable. Descartes' reasoning turns on itself here: the argument that our senses cannot be trusted because we discover later that they were mistaken begs the question of how we can know that our subsequent discovery was correct as opposed to the original sensory perception. In other words, how can we have knowledge the second time, but not the first? Relying on the senses (generally speaking) is infinitely more rational than systematically doubting them and uming that they always tell us lies. To the average mind, this maxim goes without saying. It is only the wayward philosopher who tries to stretch his mind to the point of doubting everything (even beyond reason) who encounters the idea that his senses lie as if they were running for public office. If one is being strictly rational, the senses are in fact entirely reliable. If they provide false information, it arises only from external sources, namely: a physical defect in the perceiving part (eye, ear, etc.), a poor perspective or 'sample'(the sun was in my eyes), a faulty interpretation by the brain (no way that just happened), or an interest in the particular occurrence which leads the perceiver to "witness" attributes of the object which were not really there (that was DEFINITELY p interference!!). Absent any of these things, the senses are merely providing us with perceptions of events which are dictated by intractable physical laws, making them inherently reliable. I know that one could argue that the physical laws I am citing are themselves understood as the objects of sensory perception, and that my argument is therefore circular - but that is just more over-reaching, superstitious doubt talking. Which, of course, brings us back to Descartes:
: Descartes begins by saying that he wants to abandon all notions that can
: be called into doubt. He is intending to find other statements that can not
: be doubted and which are true under any cirstances.
This is entirely impossible. I promise you, there is no statement that you could possibly make that I could not respond to with "I doubt that." This is the folly of beginning with doubt. Once you've used doubt to begin undermining things like your sensory perception, physical laws, mathematics, etc., there is no place that doubt can't go. For example:
: That lead him to a conclusion that all
: perceptions, senses, etc, shall be doubted because we can not determine
: whether we are dreaming or not and therefore say what is real and what
: isn’t.
: Furthermore, all perceptions such as mathematics, etc. must also be
: doubted, motivated by the possible existence of an evil God
: influencing these in a way to differ from what is true and real.
I kind of want to just let that speak for itself, but I find that I can't. You the slippery slope of systematic doubt at work here. Descartes goes from being a serious thinker engaging in rational inquiry to a delirious dreamer beset by evil deities. I mean, if you really think that evil gods have created the world simply to provide themselves opportunities to deceive you, well, you've got bigger problems than an unsound epistemology -narcissism and paranoia, for starters.
Of course, I'm getting a little off-track taking jabs at Rene, but I'll try to do better. If you don't like dry, mocking criticism, and Plato doesn't do it for you either, here's my final suggestion. The (now over-used and played out) slash of Ockham's razor. No insult intended if you know what this is, but in case you don't - somewhere between Augustine and Nietsche in your great philosopher's desk reference, William of Ockham came up with a nice simple statement of what most of us just call common sense; "do not multiply entities without good and sufficient reason." In other words, the simplest explanation is usually the one that's correct. To tie that back to the present conversation, the simplest explanation would be the one that does not require malicious other-dimensional beings. To come full circle and wrap this up neatly:
: In his work, Descartes states that he doesn’t need to examine all the
: variety of opinions but the foundations on which they are bases. He says
: that if he will be able to prove that the foundations of these opinions are
: wrong, therefore the opinions themselves will be wrong as well.
I love it when you can turn someone's ideas against them, don't you? Well, maybe not if you're a logical positivist. Anyway, Descartes falls into his own trap here (again). Since his basis of systematic doubt leads him inevitably to irrationality (think evil Gods), it follows that systematic doubt is an irrational method of inquiry, and therefore must be rejected under Descartes' own rule that all thought must be guided by reason.
As an afterthought, I want to explain my dislike of Descartes. It stems from my belief that he derailed Western thought 400 or so years ago and we still haven't got back on track. The example I gave contrasting Platonic knowledge with Cartesian "knowledge" is equally useful here. Plato began his thought process with a sense of wonder. He observed, asked himself why things were the way they appeared, thought about it some, then wrote down his ideas. In turn, Descartes observed, asked himself how he could undermine belief in everything he saw, thought about it some, then wrote down his ideas. The real truth is, human beings are already great at deceiving themselves for many reasons. They don't need an exalted (ahem) philosopher to lend credibility to their self-delusion by putting his stamp on it. Since Descartes made doubt fashionable, Western thinkers have been more concerned with pointing out everything they can find that is false than with trying to discover what is true. Since Descartes, we've seen the gradual bleeding and eventual death of God, the subsequent slide to almost-nihilism with guys like Neitsche, Marxism and all it's attendant horrors, the bitter I-dont-give-a-d@mn-anymore sentiments of the existentialists, ism and the attendant Social Darwinism, and finally, Arnold Schwarzanegger became governor of California. Okay, maybe all of it wasn't directly Descartes' fault, but his ideas opened the way. So, in closing, always remember to begin with wonder and belief instead of doubt. Thank you.