With the 2016 election season in full force, here's a timeless thought from Max Weber in his 1918 lecture, "Science as a Vocation" (available various place on the web, like here and here).
“The primary task of a useful teacher is to teach his students to recognize 'inconvenient' facts--I mean facts that are inconvenient for their party opinions. And for every party opinion there are facts that are extremely inconvenient, for my own opinion no less than for others. I believe the teacher accomplishes more than a mere intellectual task if he compels his audience to accustom itself to the existence of such facts. I would be so immodest as even to apply the expression 'moral achievement,' though perhaps this may sound too grandiose for something that should go without saying.”