This article profiles Christopher Benfey, 53--an art critic for Slate, a poet, and a prolific literary essayist for such venues as "The New York Times Book Review, The New Republic," and "The New York Review of Books." His latest book, "A Summer of Hummingbirds: Love, Art, and Scandal in the Intersecting Worlds of Emily Dickinson, Mark Twain, Harriet Beecher Stowe, & Martin Johnson Heade," which rambles gracefully from anecdote to anecdote, is his most unconventional effort to date. Through a web of friendships and chance encounters, it attempts to describe what Benfey calls "an informal cult of hummingbirds" that he believes took shape in the years following the Civil War. Benfey argues that for a certain artistic and literary avant-garde, the hummingbird represented the fragmenting social order, along with the new theology of love, the new science of evolution, and the lure of the exotic and erotic. His characters, who also include the popular preacher Henry Ward Beecher (Stowe's brother) and the soldier-writer Thomas Wentworth Higginson, all drew, painted, discussed, collected, or wrote about hummingbirds. Heade, for example, was the pre-eminent hummingbird painter of his day. Dickinson identified with the hummingbird, the subject of a famous poem that she sent to Mabel Loomis Todd--who, it turns out, had studied painting with Heade. Stowe rescued a wounded hummingbird, which she sketched. Twain, a close friend of Beecher, was an admirer of Heade and purchased one of his paintings. All these figures, "came to see a new dynamism and movement in their lives, a brave new world of instability and evanescence," for which the hummingbird was an apt symbol.