These are strong terms, but that’s deliberate. My interest in this sort of knowledge stems from its necessity. Suppose one denies he [or anyone else] has any philosophic knowledge. Well, then it is possible that he is mistaken in the denial itself. In other words, he could actually accept that he necessarily has such knowledge. But then it is evident that anything he says could, in fact, mean the contrary. He would not even be able to state his absolute, unmistakable acceptance of this as a logical consequence. He would not even be able to know what a mistake is. In denying the possibility of the sort of knowledge I describe, it is evident one either assumes such knowledge by claiming he is not mistaken that knowledge isn’t necessary, or he implicitly admits to losing meaning and intelligibility. Both are self-defeating. Even Neurath’s boat presupposes one plank on the Good Ship Worldview that can’t be replaced: the need for a boat.
Note that the above does not suggest everyone actually possesses philosophic knowledge. It suggests everyone implicitly claims to possess philosophic knowledge. They may or may not be able to justify this and other knowledge claims.