I've been slowly working my way through Michael Polanyi's 1958 book "Personal Knowledge: Towards a Post-Critical Philosophy: A chemist and philosopher attempts to bridge the gap between fact and value, science and humanity". I find the book fascinating, and interestingly apropos to many current issues surrounding the interaction between science and policy, debates about certainty and instances where differing modern "tribes" seem to have vastly different views of reality.
Epistemology (studying how we come to know things) is closely related to the issue of semantics (meaning) which I've written about before (and see that post for further links on related topics here). In Polanyi's chapter 2, section 5, "The Nature of Assertions", his discussion nicely emphasizes essentially what I wrote on the centrality of "trust, provenance, and context" to meaning:
A sincere allegation is an act that takes place in speaking or in writing down certain symbols. Its agent is the speaking or writing person. Like all intelligent actions, such assertions have a passionate quality attached to them. They express conviction to those to whom they are addressed. [...] no sincere assertion of fact is essentially unaccompanied by feelings of intellectual satisfaction or of a persuasive desire and a sense of personal responsibility. [...] It is clear that I can make use of the sign |- to put on paper an allegation of my own; but it has not been explained how this sign is to function between different persons and between successive periods in the same person's life. [...] the symbol |- . p must be supplemented, so that it may tell us whose allegation it represents and at what time the person in question had alleged p.
Once again, this is something I expect to return to... but what I wanted to comment on today was a bit later in the book, on the issue of tacit knowledge and the "ineffable".