A subject currently discussed with some intensity is what the value of expertise is, specifically in regards to scientific matters. I will leave other fields aside for the moment, not because expertise does not exist in them, but because they don’t track as closely with qualifications. Example: given Paul Krugman’s increasingly loopy pronouncements about how an invasion from outer space to fix the financial slump (seriously), I tend to regard that Nobel Prize of his as a glorified paperweight.
Now, it is true that when you rely on the peer-reviewed literature on scientific matters, you do not guarantee that you’re always right. What you do, however, is set a strict limit on how wrong you can be. For example, someone who bases their knowledge of scientific consensus on the peer review literature is not likely to say that human activity doesn’t affect the climate, or that evolution has not shaped how we view and deal with the world (don’t know why I thought of those examples).
It is absolutely true that stuff in the journals is often found wrong. But you know what ends up showing it wrong? Stuff published in other journals. When I wrote that the original hockey stick graph was guff and had long since been overhauled, I did so citing a whole number of more recent studies, including stuff by Michael Mann himself. That is also why there is a world of difference between saying someone is wrong in science and saying someone is dishonest.
None of the above licenses the point of view, being taken by certain so-called skeptics, that since the material in the journals is subject to correction and improvement, we can just dispense with the whole system and cut to “what some bloke on the web said”.