Why has assent on even basic factual claims (beyond logically demonstrable ones, like 2 + 2 = 4) become so hard to achieve? Or, to put it slightly differently, why are we—meaning people of varied political persuasions—having so much trouble lately arriving at any broadly shared sense of the world beyond ourselves, and, even more, any consensus on which institutions, methods, or people to trust to get us there? And why, ultimately, do so many of us seem simply to have given up on the possibility of finding some truths in common? – Hedgehog Review