I just watched this the video that Jon Husband points to in comments on this blog of David Weinberger at the Library of Congress.

Jon Husband

For an interesting take on this subject, involving a sizeable audience of (I'm assuming) senior librarian types at the USA Library of Congress, watch David Weinberger trace knowledge from Plato and Aristotle through Descartes to the clash between official objectivity and personal subjectivity, moving deftly to the power and believability of human voice on ... of all things ... blogs (especially those with comments capability, which I think must be well in the majority ;-)