How to Be a Citizen of Earth: Learning from the Children of Palau

“I shall not take what is not given. I shall not harm what does not harm me. The only footprints I shall leave are those that will wash away.”

Looking back on his long and luminous life at age ninety-three, the great cellist Pablo Casals held up one great task before humanity: “to make this world worthy of its children” — those inheritors of the present and living emissaries of the future, whose souls, in Kahlil Gibran’s memorable words, “dwell in the house of tomorrow.” To make of that house a...