Like other species, we have a culture. But compared with other species, we are strangely unstable: human cultures self-transform, diverge, and multiply at bewildering speed. They vary, radically and rapidly, from time to time and place to place. And the way we live – our manners, morals, habits, experiences, relationships, technology, values – seems to be changing at an ever-accelerating pace. Ultimately, no environmental conditions, no genetic legacy, no predictable patterns, no scientific laws determine our behaviour. We can imagine and re-imagine our world at will. The historian’s award-winning books include Civilizations; Millennium; 1492: The Year Our World Began, and Pathfinders: A Global History of Exploration.