What field of scientific endeavour is he talking about? Hint: it is not climate science.
...the community itself is tiny. In most fields...there are few experts.... In every field, there are “bosses” who proclaim the correctness or incorrectness of a new result, and its importance or unimportance. Sometimes they disagree, like gang leaders fighting over turf.
We...believe that the [results] are correct because a political consensus has developed in support of their correctness.
Part of the problem is refereeing. Many (I think most) papers in most refereed journals are not refereed. There is a presumptive referee who looks at the paper, reads the introduction and the statements of the results...and, if everything seems okay, recommends publication.... When I read a journal article, I often find mistakes. Whether I can fix them is irrelevant. The literature is unreliable.
we rely on the judgments of the bosses in the field.... even in [super secret scientific field of endeavour, truth can be political.
Click through the link for your answer or, if you want to do some pointless internet sleuthing, the author's name is Melvyn B. Nathanson.
Keep it in mind next time you run into Michael Crichton, and he says something dorky like
There is no such thing as consensus science. If it's consensus, it isn't science.