In 1913, Franz Marc, one of the key figures of German Expressionism, created a masterpiece: The Fate of the Animals. With its violent slashes of color and line, the painting seemed to pre-figure both the outbreak of World War I and, more eerily, Marc's own death in an artillery barrage at the Battle of Verdun three years later. With his signature blend of wide-ranging erudition and lively, accessible prose, Morgan...