To remember James Russell Lowell primarily as a humorist might seem to encourage one to ignore the great bulk of his literary work, at least as it is measured quantitatively, and to focus on that aspect of his achievement about which he sometimes felt troubled. Lyric poet, reformer, familiar essayist, critic, editor, professor of belles-lettres, and diplomat: these titles barely begin to encompass the full range of his remarkable and fortunate existence, a life that was in Charles Eliot Norton's opinion representative of the best and therefore rarest qualities of its time. But Norton, Lowell's literary executor, never much appreciated humor, Lowell's or anyone else's, and he missed recognizing that Lowell was most representative in his love of laughter. Lowell was one of those who looked at the world with a laughing eye. In his best poetry (at least those few poems that encourage re-reading), his essays, his...