DivideByZero wrote:I read somewhere that three criteria must be met in order to achieve knowledge.
1) one must believe it to know it
2) truth must be independent from people
3) a true statement must always remain true forever
You got that wrong. 3 is wrong because I know that I am sitting in a chair, even though in a few minutes I will be standing in the kitchen. (OK, 3 is arguable if you are clever enough, but I'm going to let you figure out how.)
The three classical criteria (from Plato, restated in various ways) are:
Edmund Gettier, restating Plato wrote:S knows that P if and only if
1. P is true,
2. S believes that P, and
3. S is justified in believing that P.
Various restatements include:
Chrisholm wrote:S knows that P if and only if
1. S accepts P,
2. S has adequate evidence for P, and
3. P is true.
Edmund Gettier addressed these criteria in his famous paper, "Is True Justified Belief Knowledge?". You can google "Gettier", "Gettier problem", or "Is True Justified Belief Knowledge" and get this link to it
on the first page. In short, Gettier pretty conclusively showed that, no, true justified belief is not necessarily knowledge. In the past 46 years or so, philosophers have worked on new definitions of knowledge, but as usual, no one agrees on one yet.
Gettier, by the way, is one of my philosophical heroes because, aside from that single three page paper that overthrew millenia of philosophical agreement on the definition of "knowledge", he published almost nothing else in his entire career. This came up when he applied for tenure. From what I've heard, Gettier responded by bringing in many of the hundreds of papers and books that had already been written in response to his paper. In recognition of the impact of "Is Justified Belief Knowledge?", Gettier was granted tenure and hasn't published since.
Fascism: If you're not with us you're against us.
Leftism: If you're not part of the solution you're part of the problem.
Perfection is an unattainable goal.