According to Edge.org:
"In 1959 C.P. Snow published a book titled The Two Cultures. On the one hand, there were the literary intellectuals; on the other, the scientists. He noted with incredulity that during the 1930s the literary intellectuals, while no one was looking, took to referring to themselves as "the intellectuals," as though there were no others. This new definition by the "men of letters" excluded scientists such as the astronomer Edwin Hubble, the mathematician John von Neumann, the cyberneticist Norbert Wiener, and the physicists Albert Einstein, Niels Bohr, and Werner Heisenberg."
Did historians believe they had a form of knowledge that was certain or nearly so? What were the causes of the perceived and actual status of history as a field of knowledge today (aka just prior to 20 years ago) versus this claimed transition period?
I wish I could find the source, but I vaguely remember someone claiming that history used to be considered a highly respectable and almost certain for of knowledge not too long ago.
But then the marxists screwed everything up. Over simplified? Yes. But, that doesn't change the basic question. I am only commenting in hope to pique someone's interest who knows more. I do not even know if most historians view their field as reliable as, say biology or chemistry.
Since history is rarely testable (though their are exceptions) and nearly never testable and conformable to double blind testing, it seems like its knowledge will always be weak, except in obvious cases. Except in obvious cases where their are exceptions. I keep saying their are exceptions, since most people would want to say, 'no that's all wrong'. I don't mean to overgeneralize without nuance.