The American idea, as I understand it, is to trust people to know their own minds and to act in their own enlightened self-interest, with a necessary respect for others. Totalitarian governments promise relief for deprived and desperate people, but in the end are maintained in power by terrorism from above rather than the consent of the governed. Empowerment of the individual was the idea in 1857, and after a century and a half of travail and misadventure among human societies, there is no better idea left standing. The idea of individual freedom, undermined by a collectivist tide in the first half of the last century and disregarded by radical Islam today, now spreads through an electronic culture of music, television, and the Internet, even under governments fearful of losing control.

Not only are ordinary citizens to be trusted, in the American idea, but leaders of government, too. Those who have lost the people’s trust can be voted out. To be sure, there is a lag in the process, but a process more immediately responsive to the people’s will might have ousted Lincoln and Washington in their unpopular moments. A certain trust in a nation’s overall soundness and stability is implied in the contract between the governed and the governors. American democracy speaks not just in votes and policies, but in the buoyancy, good nature, and mutual tolerance of its people. These qualities persist even in difficult times—and what times are devoid of difficulties, of contention and conflict and challenge? The American idea builds them in, creating not a static paradise but a productively competitive section of the Earth’s humanity.

The challenges ahead? A fury against liberal civilization by the world’s poor, who have nothing to lose; a ruinous further depletion of the world’s natural assets; a global warming that will change world climate and with it world geopolitics. The American idea, promulgated in a land of plenty, must prepare to sustain itself in a world of scarcity.