IEP summarises:
“Critical Rationalism” is the name Karl Popper (1902-1994) gave to a modest and self-critical rationalism. He contrasted this view with “uncritical or comprehensive rationalism,” the received justificationist view that only what can be proved by reason and/or experience should be accepted. Popper argued that comprehensive rationalism cannot explain how proof is possible and that it leads to inconsistencies. Critical rationalism today is the project of extending Popper’s approach to all areas of thought and action. In each field the central task of critical rationalism is to replace allegedly justificatory methods with critical ones.
A common summary of this is that it replaces knowledge as justified, true belief, with “knowledge is unjustified untrue unbelief.” That is, we see here the ill advised privileging of hyperskepticism.
The quick answer is to update our understanding, based on how well informed people of common good sense generally use “knowledge.” Knowledge is a term of the people, not some abstruse, rarefied, dubious philosophical notion. And it is a term that is sound,
Namely, and following Plantinga, Gettier and others, knowledge is warranted, credibly true [and reliable] belief, i.e. it includes strong form cases where what is known is absolutely certain, AND a wider, weaker sense where what we claim to know is tested and found reliable, but is open to correction for cause. Newtonian dynamics counted as knowledge before the rise of modern physics and with modification to recognise limitations it still counts as knowledge. This is a paradigm case.
But doesn’t that come down to the same thing as critical rationalism and its focus on what is hard to criticise as what counts for now as “knowledge”?
Not at all.
First, the confident but open to correction spirit of warrant and tested reliability is utterly different from the cramped, distorted thought that naturally flows from the blunder of privileging selective or even global hyperskepticism.
Second, inference to the best explanation and wider observational, inductive approaches — the vast majority of common, day to day knowledge and professional practice — is not put under the chilling effect of dismissive, undue suspicion.
Third, knowledge is accepted as a commonplace phenomenon, not a privilege of the elite few, undermining the subtext of contempt that reeks out of far too much of skeptical discussion.
And if you imagine these considerations are of little weight, that is because you are part of the problem. END