Facts as the product of repeated corroborations (not consensus) and the reasoned interpretation of writings and artifacts.

From Science and Technology in World History, Volume 3 by David Deming.  

I have tried to emphasize facts over opinions. In the experimental sciences a "fact" refers to an observation that has been repeatedly corroborated. But in the study of history, a "fact" usually refers to a citation to the pertinent literature. The past can not be observed directly, it can only be reconstructed from extant writings and artifacts. There are limitations and problems inherent in these sources. Nevertheless, a meticulous documentation of sources opens the framework of an historical synthesis for inspection followed by discussion and corroboration or falsification.

If the study of history is ever to be a science, historians must inculcate an appreciation for facts over opinions. Facts are "stubborn things." Facts persist, while opinions and interpretations change every generation. I endeavor to write a history that endures, not one that is superficial, or constructed as a tendentious search to justify some predetermined moral or ideological cause.

Facts as the product of repeated corroborations (not consensus) and the reasoned interpretation of writings and artifacts.  How far the Mandarin Class have drifted from these reasonable positions.