What does it mean to "know" something? To have knowledge?

[Silent3]

At the risk of wading deep into "tl;dnr" territory (but still brief compared to weightier tomes an the subject of epistemology)...

Like many words, "knowledge" has a variety of meanings and usages. I think if you look at how this word is typically used, however, the core concept is possession of objective truth, possession of factual information. Experience, perception, deduction, intuition, and raw information do not become "knowledge" in any deep sense of that word until they are subjected to some form of objective verification.

I know many people love to treat the notion of objective knowledge as if it were merely "one side of the coin", or worse, some oh-so-terribly limiting and blinding obstacle to supposedly "greater knowledge" and "greater truth", but do those objections stand up well to critical examination, if one strives for a consistent and clear idea of what "knowledge" means?

What happens when you try to get past the promotion of vagueness as a virtue, past carelessly or deliberately slippery word usage, or confusing the flexibility of words with flexibility of the meanings and intents behind those words?

Consider the common phrase, "I thought I knew". When is that phrase used?

Generally it is used when we have taken a statement or idea to be factually true, then that statement or idea is later held up to scrutiny, and under scrutiny the idea fails. We do not treat the failed idea as something which once was knowledge, but no longer is knowledge, we treat it as something which we had mistakenly classified as knowledge, but never was actual knowledge.

Does this distinction which nearly all of us commonly make between real, actual knowledge and mistaken knowledge make sense by any other light than the light of objective evidence? How else can that which is once thought to be knowledge lose that status unless there exists, at least hypothetically if not always in actual practice, a standard by which information can be tested and, when appropriate, falsified?

To the extent that we treat some fairly trivial ideas, thoughts, and claims as knowledge, even when they haven't been subjected to objective verification, when they may in fact not be particularly amenable to objective verification, is in my opinion less an expansion of the domain of knowledge and more a practical concession to the difficulty of obtaining solid verification in some matters, especially when the cost/benefit ratio is too high for verification to be worthwhile or important. It is not an abandonment of the core idea of objective truth.

If knowledge is possession of facts, then what makes a fact a fact? I would suggest that, in hypothetical form, a "fact" is something which is considered definitely and universally true. Facts are things which are not matters of opinion -- even when opinions differ on what is a fact or isn't. For practical purposes, facts can be regarded as statements or claims which can be objectively proven true to whatever degree of proof is appropriate, given the possible consequences of making an error in fact.

One can have knowledge of subjective feelings and experiences. I believe, however, the core meaning of the concept of "knowledge" leaves individual subjective experiences one step removed from being knowledge per se, but rather knowledge that -- knowledge that person X experienced sensation Y.

For example, Alice thinks the room she is in is cold. Bob, in the same room with Alice, thinks the room is warm. The difference in perception is not a difference in fact. A factual accounting of the situation simply requires recognition of the differing perceptions, and recognition of the inexact meanings of words like "cold" and "warm". Given that in most situations there would be little reason for Alice and Bob to falsely or erroneously state their own perceptions, given that each person can generally be regarded as reliable sources of information about their own perceptions, and given that nothing of great importance is likely to hinge on the truth of these matters, provisionally regarding such matters as facts, therefore matters of knowledge, is a completely reasonably thing to do, requiring no concession at all to mystical, non-objective notions about knowledge.

A clear distinction must be made between perception and interpretation of perception. Take for example a common optical illusion. A general inclination to treat a person as a reliable authority on their own perceptions, for instance that one line seems longer than the other, is not the same as a general inclination to believe that one line is actually longer than the other simply because that is what someone claims to perceive.

What about knowledge of logic and mathematics? I won't pretend that this isn't a tricky area of epistemology (people still argue over whether mathematical concepts are invented or discovered) but these subjects still can be said to be objective in that the rules and conclusions of logic and mathematics stand up to rigorous methods of proof that do not depend on anyone's personal subjective opinions or perceptions. You can play around with postulates and premises and get different results, but there are still objective conclusions which derive from well-defined postulates and premises.

I've seen intuition, mysticism, and religious revelation put forth as "ways of knowing", but these are at best sources of raw information which cannot be considered actual knowledge until the information provided is objectively validated. Whether or not such information is compelling and convincing to the individual who receives it is hardly a good reason to water down the core concept of knowledge to include such information, except perhaps in the once-removed sense of acknowledging the personal importance that information has to the individual.

The weakest concept of knowledge, while ironically also the one that can be most compelling to an individual, is that knowledge is simply that which you feel strongly must be true: you know something because, damn it, you KNOW it!

The main thing that I see intuition, mysticism, religious revelation, and "just knowing" have going for them as supposedly reliable sources of knowledge is a "count the hits, ignore the misses" accounting of their success. Intuitions that don't turn out weren't real intuitions. Failed religious revelations weren't real revelations.

Then there is also the fact that much religious and mystical so-called knowledge is carefully designed to be beyond the reach of proof or verification, answering only to the very low standard of "you can't prove me wrong!".

Based on what I've written above, I see no reason to treat an emphasis on a scientific approach to knowledge, and strong doubts concerning the validity of any other approaches, as some sort of terribly unfair limitation or prejudice. Simply expand the idea of the scientific approach to include the logic and mathematics which are the language of science, which certainly takes science beyond the "if you can't see it, hear it, taste it, touch it or smell it" caricature some people seem to love as a favorite straw man, and the scientific approach becomes the only approach that leads to a concept of "knowledge" which is consistent with deep, clear, and meaningful usage of that word.