Charles Murray’s essay, “Does America Still Have What It Takes?,” provides a brief but comprehensive treatment of an issue—the rise and fall of civilizations, cultures, or nations—that has plagued thinkers for many centuries. He mentions the ancient Roman historian Velleius Paterculus (c. 19 B.C.E. – c. 31 C.E.), who speculated on why geniuses in literature and philosophy tended to cluster into periods of intense creativity, only to yield ground quickly with the passage of time. Much later, the Muslim historian Ibn Khaldun, in his Muqaddimah (1377), contributed an important systematic treatment of historical cycles in politics and the arts.