Much of what people think they "know" is not actually based on the acquisition of information about reality, but instead on various sorts of poorly-grounded beliefs. And I think it's a huge oversight to neglect these categories in your overview.
There has been a large amount of study on these topics in the "skeptic" literature, such as:
Skeptical Inquirer magazine, published by the Committee for the Scientific Investigation of Claims of the Paranormal. Main focus is on skeptical examination of the "paranormal", but covers many other topics as well including superstitions, pseudoscience, etc.As a wise man once said, "it's not what you don't know that gets you into trouble, it's what you know that ain't so".Skeptic magazine, published by the Skeptics Society ("Dedicated to the promotion of science and critical thinking, and to the investigation of extraordinary claims and revolutionary ideas")
"Everyday Irrationality: How Pseudo-Scientists, Lunatics, and the Rest of Us Systematically Fail to Think Rationally", by Robyn M. Dawes
"How We Know What Isn't So", by Thomas Gilovich
"The New Skepticism: Inquiry and Reliable Knowledge", by Paul Kurtz
"How Do You Know It's True?: Discovering the Difference Between Science and Superstition", by Hyman Ruchlis
As such, understanding how people (including ourselves) "know what ain't so" is a critically important subject, and yet few disciplines actually pay much attention to it (except to exploit it, as by advertisers, magicians, con men, and propagandists). So the "skeptic" community came together to study that topic and provide information to the public about how not to get snookered (by yourself, even, not just by others).
Skeptics are often disliked by just about every group, because they usually act as "party poopers" pointing out the flaws in various comfortable presumptions, but they're the experts on how and why people believe various things that "ain't so" -- and how to learn to think more critically (about other people's claims, as well as about your own beliefs) and how to use more reliable methods of learning and understanding.
The skeptic literature also has frequent articles on how con men, hucksters, and other charlatans work their trades, so that you can learn how not to fall for them. There's also a whole sub-genre on how "psychics" appear to know more than they do, so as to sucker in clients and followers. For example: Hyman, Ray. "'Cold Reading': How to Convince Strangers that You Know All About Them", The Skeptical Inquirer, Spring/Sumer 1977.
I always like to point out that it is our natural aversion to truth that causes the most trouble.
So if I get your drift(from the whole post)... Your saying basically ...
There are MORE than one sucker born every minute..
Right.?.
Can you give assurances, Ichneumon, that the insights of "party-pooper skeptics" cannot in principle be included in that vast category of "bogus knowledge" which includes "visions, intuition, hallucinations, faulty conclusions, jumping to conclusions, fallacious reasoning, prejudices, 'common sense', revisionism, deceit by others, faulty memories, 'recovered' memories, bias, preconceptions, indoctrination, propaganda, emotions, superstitions, rationalizations, bandwagon groupthink, etc. etc.?"
If so, will you demonstrate why the insights of skepticism must be excluded from this nasty category? On what basis are we to rationally accept the skeptic position as not just another of the many "various comfortable presumptions?"
To me, skepticism is a variant of ideological thinking. That suspicion seems justified to me, for its basic premises are hidden as is usually the case with ideologies. If we are to penetrate the mysteries of skepticism, then it seems to me we first need to have disclosure of the hidden premise(s).
Can you help with this?
I strongly agree with betty boop that skepticism is an ideology - I assert that the ideology is metaphysical naturalism as b_sharp's Sagan list would also suggest.
And much like my list of "types" of "knowledge" and valuations of certainties begins with Spiritual understanding - the skeptic list would surely come with that materialist prejudice from the very top.
That is probably why it is both futile and frustrating for correspondents to try to argue with me using the logical tools of metaphysical naturalism. They probably believe they are being quite intellectual and logical - but to me, they appear tunnel-visioned and uninformed. LOLOL!
The bottom line is that there are no 'right' or 'wrong' answers to the question posed by this thread. We only wish to get to know one another better.
I think skepticism is implied in the opening post of the thread, namely in its sorting of knowledge by degrees of certainty.
As a recovring behaviorist and amateur neuroscientist, I am aware that we quite literally don't know ourselves. I listed personal feelings at the top of my list of things I am certain of, but I did so with a touch of sarcasm. In the light of science, we are singularly unaware of what is going on in our heads, often to the point of not being aware of what we are feeling.
I note that this unawareness is seen by some as a virtue, leading them to assume that whatever is going on is not going on in their heads, but must be going on somewhere else. The construction of the brain doesn't lend itself to core dumps, so analysis of our inner workings is painfully slow and difficult.
Thinking about it doesn't solve the problem. Philosophers have been sayine "know thyself" for a long time, without much effect.