Knowledge is a justified, true, belief.
If someone has no beliefs, they have no knowledge.
The belief must be justified. Who decided justification?
The believer decides justification. What is sufficient justification for one person, may not be sufficient for another person. Justification is often not universal, therefore knowledge is not universal. The fact is universal, but awareness often is not. Even if awareness is universal, knowledge may not be.
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Sue and Mary are driving, looking for a museum, that neither one has ever visited. They stop and ask for directions. Sue is very familiar with the area, spent most of her life, over thirty years in the area, but that was before they built the museum. The night before she studied her old maps of the region. She did not have an address for the museum, but knew the approximate location.
Mary was new to the country, and had no knowledge of any roads or landmarks.
They ask a passerby about the museum, and how to get there. The person is a tour guide for the museum, and he still has his uniform and name badge on. He gives directions to the pair. They are very helpful to Sue, only slightly helpful to Mary. Sue asks some questions about other landmarks she remembers. The passerby answers many questions Sue has about the exact location. Every detail the passerby gives rings true, and fills in many blanks Sue had.
When the conversation is finished, Sue says she knows the location of the museum, and can drive them there. Mary has a good idea where it is, a weak belief she could guide them there. Sue had knowledge, Mary does not.
Sometimes in Science, Scientists have a belief. Using all the latest scientific techniques, they justify their beliefs. Multiple groups work independently, and arrive at the same conclusion. They all share their beliefs, by a process called peer review.
Scientists never have proof for anything. There is never sufficient justification to have final proof, but often beliefs have a scientific certainty of being factual. The evidence is overwhelming. There is no scientific evidence the fact is not true, there is ample justified scientific evidence it is true. They have knowledge. They report this knowledge to all interested parties. They share their knowledge with others, and the report from all of these scientists is sufficient justification for all interested persons to also have knowledge about the same facts. All is well.
One day scientific evidence demonstrates the fact is false. It is not true. It turns out the belief was a justified false belief. So, scientists report the new findings, the new facts, the new justified, true, beliefs.
This is how Science works. The process identifies beliefs, that are sufficiently justified, and pronounced as knowledge, only to turn out years later, to be false.
Science offers no final proof that any statement is factual, an actual occurrence. It does offer many beliefs that have been justified, and have a high probability of being factual, congruent with reality.
Science plays the odds, and has a fairly good track record. They have been on the winning side much more than the losing side.
Scientists have also had some major failures, that cost hundreds of lives, and millions of dollars. They had false beliefs, that they believed were true. Scientific truths, that turn out false, is a fact of life. This is no reason to say Scientists cannot have knowledge, simply because there is no absolute proof the beliefs are true.
In Science, justified true beliefs are knowledge, until they are demonstrated as being false. At that point, they are simply false beliefs.
In our daily lives we have knowledge, that had no scientific evidence.
Justification is not limited to Scientific evidence.
Sue had hearsay evidence, that raised her beliefs to knowledge. Mary did not share this knowledge. She may have had faith that Sue knew the exact location of the museum, a high level of confidence, but it could easily fall short of knowledge.
One a daily basis, our experiences, provide us with sufficient justification to raise our beliefs to the level of knowledge. Whether others accept our knowledge, as true, has less to do with the facts, the actual occurrences congruent with reality, and more to do with the beliefs of the other person.
