A simple test would be, "Do the findings obtained through skeptical research apply to all people, or only those people who believe skepticism to be valid?"
I can think of plenty of examples (Modern medicine and computers to name but two), but I can't think of anything discovered through skeptical research that would be a counter-example.
If the findings are applicable outside of those people who believe in the methods used to obtain them, then they are a better approximation of reality than something that cannot be applied universally.
We're still in the position of needing a method to judge if the findings are applicable to everyone. If we use skepticism, wouldn't it just be trying to prove itself with itself?
As for whether skepticism is always reliable - so far it has been. Of course, adopting a skeptical view I have to concede that in the future it is possible that we may find a situation in which skepticism doesn't work. But until that counter-example is found, if it even exists, it is reasonable to say that skepticism always works to the same degree of certainty as I can say that the earth is an oblate spheroid.
I'm not sure how we could say that we know that it has been. If skepticism only allows validation if the skeptical approach has been used, how could we know if skepticism doesn't miss things? Aside from error and the fallibility of those interpreting the evidence, if, for example, the doubting process required in skepticism somehow skewed the results itself because of some kind of bias involving people only seeing what they expect to see, would skepticism be able to pick that up in every case?
When skepticism is applied, does the belief stand up to scrutiny? If yes, then it is not irrational, if no then it is irrational.
Doesn't this suggest that we can't trust our own senses, memories and thought processes, let alone anyone else's? Beliefs that everyone holds are based on such things and many wouldn't stand up to skeptic scrutiny. By this definition, it would be irrational for me to believe what my mother said was the first word I spoke and irrational for my mother to believe that it was my first word. It would be irrational to believe that I like the things I like. If we follow this logic through, anything I learn at all
could be an irrational belief, because when I'm taught, I have no idea if what my teacher is saying will stand up to scrutiny and I can't trust my memory to have learned it accurately, nor my thought processes to have understood it correctly. It would just be by sheer luck if any of my beliefs stand up to someone else's scrutiny and are therefore objectively deemed rational.
With all due respect, that's not how peer review works. The objections you raise are the very things that peer review is designed to catch - that it has passed such a process is indicative of a reasonable degree of scientific rigour.
One would also not want to posit some sort of scientific peer review conspiracy without any evidence to support the claim.
You're probably right about the particular points I raised, but my point was really more about trusting your own judgement, than trying to suggest any flaws in the peer review process. The old guy who lives in a cottage by the loch, who (so long as he comes alone) has been feeding crab-sticks every day to Nessie for the last 30 years, would just laugh at piles of rigorously checked scientific evidence that show that it's almost impossible for a monster to be living in the loch. Just because everyone else thinks he a nutter, doesn't mean he's wrong or irrational to trust his own judgement.
If I did my own experiments in my basement on something, would it be reasonable to believe my own results?
Depends on whether or not your results could stand up to scrutiny or not.
"Could" or "do"? If I think they could stand up to scrutiny, is it reasonable to believe my own results or would it only be reasonable after such scrutiny? If someone else's scrutiny disagrees, why should I believe their results over my own? I know what I saw far better than I know what they saw.
You should apply skepticism in all parts of your life, yes, but to have a blind spot is to simply be human.
Also, you say that to judge whether or not it is raining we use subjective experience - I don't quite follow your reasoning here. I can see the rain, as can any others underneath or near the rain cloud. I can hear the rain - again, as can others. And most importantly, if I step into the rain, I will get wet - something that I and others can objectively observe.
I don't see how you can claim that it is subjective evidence we use to tell us whether or not it is raining...
If I am alone somewhere and it rains, it may as well be a subjective experience, just like seeing the monster. There could be other explanations for my experience, so I shouldn't trust that it's actually raining on this evidence alone. Someone comes along and shouts "Hey, get out of the rain! You'll be soaked through to the skin!", but this is anecdotal evidence, so I can't trust that either...anyway you get the idea. I'm trying to determine whether one really should apply skepticism to all parts of their life, or whether such an approach leads to madness and probably an early death.