Is this even possible? Not if we actually know it.
About once a month our philosopher daughter, Shirley, and I engage in a discussion of epistemology. Often this conversation, by necessity, wonders into metaphysics. This morning was no exception. I will not rehearse our conversation except to say that it was motivated by my own comments about a discussion of historiography underway (again) on the Biblical-Studies discussion list. I will reflect on what we can know, the status of Richard III as anti-hero.
“So much of what we know about him currently is wrong, and in the past we accepted the Tudor version of history unquestionably,” she [Philippa Langley] said. “But not anymore.” [Washington Post]
No, “so much of what we think about him currently (may be) wrong.” If it is wrong we do not know it. It is but our opinion; we believe it. The fact of the matter concerning Richard III or anything else is independent of our opinion. Knowledge always entails some kind of coincidence between opinion and the fact of the matter underling that opinion. While philosophers have added much nuance over the millennia, this core principle has survived since Plato (see Theaetetus, 199ff.). Gettier (or Russell for that matter) didn’t disprove this, he raised a rather serious question about the third condition in classical epistemology, the nature of justification (Plato’s logos in Theaetetus) for one’s true belief.
Langley is likely speaking informally. But informal usage can easily migrate to formal discussion. What we know cannot be contrary to the fact of the matter. If it turns out to be, then we didn’t know it. For this reason, much of what we think we know is at best probabilistic and likely problematic. Rigorous methodology doesn’t change that. It does make our opinions more or less likely, more or less pernicious and ultimately less problematic.
All that said, there are many opinions where the justification is so strong that it is pernicious to think that that opinion does not align well with the fact of the matter. Evolution is an obvious example. Global warming is another. Opinion on any unjustified or even poorly justified religious doctrine is pernicious.