A commenter on the Pieper post notes that Dallas Willard has a understanding of the belief-knowledge relation (or lack of relation) similar to that of Pieper. A little searching brought me to the following passage in Willard's Knowledge and Naturalism which substantiates the commenter's suggestion (I have bolded the parts relevant to my current concerns):
The absence of any reference to belief in my statements on knowledge and knowing will be immediately noticed. The absence is intended, and though rare today in discussions of knowledge it is by no means unique in the history of the theory of knowledge.14 Even such a resolute Naturalist as Roy Wood Sellars specifies the nature of knowledge without reference to belief.15
Belief I understand to be some degree of readiness to act as if such and such (the content believed) were the case. Everyone concedes that one can believe where one does not know. But it is now widely assumed that you cannot know what you do not believe. Hence the well known analysis of knowledge as "justified, true belief." But this seems to me, as it has to numerous others, to be a mistake. Belief is, as Hume correctly held, a passion. It is something that happens to us. Thought, observation and testing, even knowledge itself, can be sources of belief, and indeed should be. But one may actually know (dispositionally, occurrently) without believing what one knows.
Whether or not one believes what one represents truly and has an appropriate basis for so representing, depends on factors that are irrelevant to truth, understanding and evidence. It depends, one might simply say, on how rational one is. Now I do not think that this point about belief in relation to knowledge is essential to the rest of this paper, but I mention it to indicate that the absence of any reference to belief in my general description of knowledge is not an oversight. Belief is not, I think, a necessary component of knowledge, though one would like to believe that knowledge would have some influence upon belief, and no doubt it often does.
In addition, it seems to me that specification of knowledge in terms of belief is a harmfully tendentious characterization, favoring the naturalization of knowledge. This is because belief has an essential tie to action, and is therefore easily located in the natural world–say as a mere tendency of the physical organism to behave in certain ways. I suspect that it is the almost overwhelming Empiricist–and in that sense Naturalist–tendency of thought in our time that has created the general presumption that knowledge must be some kind of belief. Hence we must here at least question that presumption; and, I believe, when questioned it will not prove to be obvious or, finally, sustainable.
I am not sure how deep the Pieper-Willard similarity on this topic runs, but it is worth exploring. One caveat: Willard above agrees with Hume that belief is a passion, "something that happens to us." This does not appear to comport with Pieper's doxastic voluntarism.
I am also puzzled by this sentence of Willard's: "But one may actually know (dispositionally, occurrently) without believing what one knows." The dispositional and the occurrent are opposites. Why does Willard bracket them together? Furthermore, if I actually know something, if my knowing is 'in act' as a Scholastic might put it, then my knowing is occurrent, and there is nothing potential or dispositional about it. Finally, what would be an example of Willard's point?