"Americans and Europeans alike sometimes forget how unique is the United States of America. No other nation has been created so swiftly and successfully. No other nation has been built upon an idea — the idea of liberty."  —Margaret Thatcher, 1991

Two weeks ago I joined hundreds of lawyers, judges and policy experts for a gathering of the Federalist Society in Washington, D.C. The occasion, the Barbara K. Olson Memorial Lecture; the speaker, Sen. Tom Cotton of Arkansas.

The Federalist Society established this annual lecture 15 years ago to honor a life cut short. A lawyer and commentator with a distinguished career in public service, Barbara Olson was a great friend of the Federalist Society and the ideas it espouses — individual liberty, limited government and the rule of law. Olson died on Sept. 11, 2001, a passenger on American Airlines Flight 77, which crashed into the Pentagon. 

Cotton used his address to highlight America’s exceptional promise, both for those born here and those who would come: “We should take pride that we live in a nation people are willing to die to reach, not escape.” Our duty, he said, is to do more than simply pay tribute to Olson and the thousands killed that day, but to live lives that preserve and advance liberty. Cotton’s remarks were especially poignant as news of the Paris terror attacks came to us that very day.

Later that night my colleague Patrick Wright and I walked down to a symbol of a different era of crisis. Abraham Lincoln’s words etched in marble and Dr. King’s 1963 speech at the Lincoln Memorial remind us again of the idea of liberty — the proposition that “all men are created equal.”

Our last stop was the Tomb of the Unknown Soldier to watch the changing of the guard. I’ve made dozens of trips to D.C. and yet this was my first time viewing the ceremony. The guard relinquishes his watch and passes orders to the new sentry: “Remain as directed.” Through rain, snow or terror … remain as directed.

Against this backdrop is the hysteria of students on campus who demand intellectual childproofing to shield them from contrarian viewpoints. Trigger warnings, safe spaces, shouting down opponents and lodging protests over graduation speakers all flow from the same troubling assumption that truth can be attained through a militantly enforced silence. Occupy Wall Street has devolved to Occupy My Bubble.

It would be easy enough to deride the childish expectation that all disagreement can be avoided. Instead, we should recognize an opportunity to defend one of the pillars of the idea of America. As a free people we are eager to embrace vibrant debate. Justice Louis Brandeis explained this when he wrote, “Freedom to think as you will and to speak as you think are means indispensable to the discovery and spread of political truth. … Discussion affords ordinarily adequate protection against the dissemination of noxious doctrine.” Those who would silence speech would suffocate democracy.

Sacrifice, equality, duty and free expression. Ideas worth the founding of a nation, and worth our vigilance today.