Descartes' criterion for truth, do you ever use it?

Question

"...reason now persuades me that I should withold my assent no less carefully from things which are not plainly certain and indubitable than what I would to what is patently false, it will be sufficient justification for rejecting them all, if I find in each one of them some reason for doubt."

This was THE skeptical method to finding absolute truth.

Do you ever tell youself?-- well this set of data is only, merely probable therefore let's pretend that it is absolutely false, so that I can find a firm foundation to my knowledge.

Or is this criterion really contrived and impossible in everyday life?

Answer 1

Actually, Descartes himself was not a skeptic! In fact, he proposed several arguments for God's existence using his own philosophy. However, there are several problem with Descartes philosophy itself. For instance, why should one doubt everything that is doubtable? One can doubt whether Descartes' starting point is the best way to approach the world. One thing Descartes couldn't doubt was the fact that he was actually doubting!

Descartes began his philosophy in thought (indubitable thought) and then moved to reality. He reasoned "I think, therefore, I am." In reality, however, "I am, therefore, I think." He literally got de carte before de horse!

Once one begins in the realm of thought apart from reality, he or she can never legitimately break out of the realm of pure thought. Just is the fate of any rationalism or idealism that does not begin within existence.

Answer 2

The difficulty for Descartes was certainty. Once he applied his method of doubt, there was very little left that could be known with certainty (perhaps just "I think; I am", the actual words he uses in the Meditations).

We might require certainty for some kinds of things (mathematics and logic, for example). And there, yes, in a sense I do use Descartes criterion, though generally without realising it.

But for most affairs of the world, including the "deductions" of super-sleuth Sherlock Holmes, we base our judgment on probabilities, not mere possibilities. The weaker criteria for truth and knowledge, based in probability, led to the epistemological view called fallabilism, which is the reigning view today.

Fallabilists think that belief should track evidence, and commitment to beliefs should be based on a preponderance of evidence. Whatever is most probably true, on the basis of the best evidence available is what we should believe.

We've come a long way since Descartes, thankfully.

Answer 3

Descartes boiled it down to " I am a thinking thing" as the only absolute truth. I don't use his method in everyday situations, but I do give it some credit. When trying to see things from objective perspectives I take into account that all I can really know beyond a shadow of a doubt is that I too am a "thinking thing".

Answer 4

Truth that philosphy seeks can't be figured out on frameworks of rationale and reasoning and that's trouble. As human beings, we need security and predictability. When it doesn't exist, we narrow the definition of our world and force fit the available knowledge to form the definitions to feel more secure and in control. Examples from real world:
a) When we cross the road, there is very low probability that we will get hit by the car. So we convince ourself that we can safely cross the cross because no one is going to hit us. In this instance, we told ourselves, immediately possibility of someone coming and hitting us is false.
b) Paranormal phenomenons: It happens with few. Doesn't with others. For those it doesn't happen, we consider only a skeptic view and convince ourselves that it is false.
c) Progression from Faith based laws to Newton's law to Einstein law is classic example. Before Newton's law was formed, there were only faith based system because that's best data people had in their hand. Then based on level of precision of data that Newton could have, he formed more accurate formula. With even more precise data points, Einstien create next level of formula that was deemed false previously.

I hope I'm able to drive the discussion to right direction and able to help on this.

Answer 5

I don't think philosophy is an adequate tool for everyday life, in fact, we actually use other heuristics to assess and make decisions. However, we can use more powerful heuristics - or philosophy, especially epistemology - when faced with more important situations pr reviewing previous assessments. They are our intellectual big guns.

Answer 6

To sum up the words of Sir Arthur Conan Doyle: "When you have eliminated the impossible, that which remains - however improbable - must be the truth."