Not necessarily. Even my wide definition of foundationalism excludes a lot of major thinkers (Putnam, Rorty, all of postmodernism, Gordon Clark) My interest was in seeing what the two have in common. I do not think they are synonyms. I hold to PBB. There is nothing wrong with it. I just reject the modern construals of it. I don't fault CvT for holding to PBB (though that is more true of Bahnsen than CvT). Most Clarkians told me that to the degree they keep up with modern discussions, they hold to something like Coherentism. That was Geisler's reading of Clark, anyway. That is interesting about indirectly provingit. Why do research at all, then? But to find the answer to a question.