The first World War in so many ways shaped the 20th century and really remade our world for the worse.

Work is hard. Distractions are plentiful. And time is short.

I think [George] Orwell is right. There are certainly moments when political differences appear minor, and someone can claim to be non-political or to want to stay out of the fray, but today is not one of those moments.

Even [Ernst] Hemingway, perhaps the most intentionally non-political of American writers, became passionately partisan during the Spanish Civil War.

How many really great writers are there who are totally non-political? You can hear the French Revolution in the poetry of [Percy Bysshe] Shelly and [John] Wordsworth; you can sense the vast inequalities of Tsarist Russia in [Anton] Chekhov and [Lev] Tolstoy.

Some 2,800 Americans went to Spain [during the Spanish Civil War], and it was, by far, the largest number of Americans before or since who've ever joined somebody else's civil war. I think they were primarily people who were deeply alarmed by the menace of fascism. They saw this on the horizon. I quote one volunteer, Maury Colow of New York, who said, "for us it was never Franco, it was always Hitler."

All of us living in today's world are facing an enormous crisis - arguably the greatest that humanity has ever faced - in the form of man-made global warming; one can't be neutral at such a moment. It's like claiming to be neutral if you're living in Germany in 1933.