

I think it’s a reaction to another institutional tendency, which is to treat the best known theories as if they were incontrovertible facts.
Science and history are largely the search for closer and closer approximations to truth, but those approximations are always flawed and incomplete. And if they’re presented as already-attained truths, a critic can point out the flaws as evidence of deliberate deception—and then present any alternative they like without its being subjected to the same scrutiny.
The two that immediately come to mind are Clarence Darrow and Cicero.