“More generally, I fear that we are becoming disconnected from the ideals that have long inspired and united us. When we laugh, it is more often at each other than with each other. The list of topics that can’t be discussed without blowing up a family or college reunion is lengthening. We don’t just disagree; we are astonished at the views that others hold to be self-evident. We seem to be living in the same country but different galaxies—and most of us lack the patience to explore the space between. This weakens us and does, indeed, make us susceptible.”