Lately I've been hearing abundant apocalyptic rhetoric about the collapse of traditional Western norms of critical thinking, free inquiry, and tolerance.  The story, roughly, is that after a century of unprecedented intellectual freedom, a new generation of barbarians - mostly "social justice warriors," with some alt-righters thrown in - has suddenly emerged in our midst.  And they're quite likely to get their way, because most of us have forgotten what critical thinking, free inquiry, and tolerance are all about. As...