Knowledge need not be Justified, True nor Believed.
The misconception that knowledge is “Justified True Belief” goes back at least to Plato. So-called “Gettier problems” are problems only for this ancient conception of knowledge, but not for the more modern and correct epistemology of Karl Popper. Popper’s “critical rationalism” is often written off as being a philosophy of “falsificationism”. But this would be like dismissing the work of Einstein as the “physics of light speed”.
Popper’s vision is one of knowledge as useful information, by which we mean knowledge that solves a problem. Information counts as knowledge, therefore, if it fulfills this simple purpose. Anyone who has ever studied high school physics will have learned Newton’s Universal Law of gravitation. They will know it. It is that knowledge which propelled people to the moon accurately. But the thing about that theory of gravity is that it is known to be, strictly, false. A crucial experiment conducted by physicists Frank Dyson and Arthur Eddington in 1919 decided between the two competing theories of gravity at the time: Einstein’s General Theory of Relativity and Newton’s Universal Law of Gravitation. Starlight, during a solar eclipse was found to be bent by an amount predicted by Einstein’s theory and not Newton’s so-called “law”. We thus know Newton’s idea of gravity to be, actually false. And because it has been refuted by observation, we are not justified in thinking it true. And today, any physicist who actually claimed to believe Newton’s Law of Gravity would be thought an impostor. And yet: Newton’s theory is very useful and solves many problems. It can still fly people to the moon, it can be used to predict tides, the fall of rocks and the movement of celestial bodies to some degree. It remains an important part of our knowledge — individually should we learn it, and collectively as a civilization. And yet, it is not justified, nor true, nor believed by any sensible knowledgeable person.
Knowledge is not “justified true belief”. Yet even today philosophers continue to debate this long ago refuted trope in epistemology. The fact is: Karl Popper explained what knowledge was and few people took him seriously. Knowledge is conjectured and remains always tentative as is it tested against reality. Criticisms, including experimental tests in the case of science can be brought to bear against it and when claims survive against rivals, we are right to call that claim knowledge. But we must keep in mind that knowledge can always be refuted and indeed we should expect even our most cherished theories to eventually turn out, in the final analysis, to be false. And yet, if the knowledge has been useful to us by solving some problem, then like Newton’s law of gravity…knowledge it remains.
Further Reading: “Objective Knowledge” by Karl Popper
“The Beginning of Infinity” by David Deutsch