First, from "A Crime in the Cancer Lab," by Theodora Ross:
Only after gathering real evidence did we discover the truth. One good experiment (videotaping the event) was worth more than all the guesses -- all of which turned out to be wrong.
We need to test what we believe, not trust it.
Second, from "When Mrs. May Met 'Mr. Brexit,'" by Jonathan Coe (quoting Henry Fielding):
A very wholesome and comfortable doctrine, to which we have but one objection, namely, that it is not true.
Both quotes address the centrality of provable facts in law, social science, journalism, history, and other evidence-based disciplines.