BERLIN — In a world scarred by violence, terrorism, and war, it is easy to grow pessimistic. Even the freest societies seem to move inexorably towards a more expansive and expensive state.

And yet. Although, as Thomas Jefferson once noted, the normal course of events is for liberty to yield, it is not always so. Political liberation is possible. And it is among the most exhilarating human experience.

A few months ago Iraqis joyously stamped their feet on the ruined icons of Saddam Hussein. Twelve years ago Soviet citizens pulled down the statue of Felix Dzerhinsky, first head of the hated secret police, in the aftermath of the failed coup in 1991.

And 14 years ago Germans destroyed the ultimate symbol of political slavery and oppression: the Berlin Wall. It is a memory kept alive at the Mauer Museum, also known as the Haus Am Checkpoint Charlie, located near the old border crossing between East and West. It is a must visit for anyone who doubts people’s commitment to liberty and the durability of the human spirit.

World War II left Germany divided. The political wreckage that constituted Europe in 1945 today seems of another age, but it was still fresh in August 1961. Although the Soviet Union had imposed an Iron Curtain across Europe, Berlin offered an escape hatch.

A single city administered and defended by the two contending alliances, Berlin was the one spot on the continent where Communist subjects could walk to freedom. And they did, in the thousands.

The human tide threatened the future of the East German state, the so-called German Democratic Republic. The best and the brightest, the young and the ambitious, simply walked across the border. Equally important, the endless flow of refugees embarrassed the Soviet Union: Why were thousands and thousands of people running away from the Communist paradise?

On August 13, 1961 the thugs who ruled the GDR and USSR responded in the only way that they could: They walled their people in. Construction of the Berlin Wall began, first with a string of barbed wire, then with a wall, and finally with ever more sophisticated and deadly defenses.

Heavily defended borders were nothing new. No one would blink at tank obstacles and automatic firing mechanisms to prevent outside invasion. But unique was Communism’s goal of imprisoning its own people. Nearly 70 miles of walls encircled Berlin.

The symbol of Germany’s division was Checkpoint Charlie, the most famous border crossing. U.S. and Soviet tanks confronted each other at this spot; nearby bricklayer Peter Fechter died while attempting to escape. In 1963 the Wall Museum was opened yards away.

The Wall highlighted the triumph of the human spirit over enormous, monstrous evil. Museum exhibits include specially designed automobiles to conceal escapees, chairlifts that were used from buildings adjoining the Wall, tunneling equipment, balloons, a motorized glider, and even a mini-submarine.

And there are the stories. Accounts of those who escaped. Examples of those who dedicated their lives to helping people to be free.

There also are stories of those who failed. Some who ended up in prison. Westerners who were arrested and even kidnapped. And some who died.

All told, 5,075 people are known to have escaped despite the Wall. Unfortunately, 176 died in the attempt; nearly 800 more were killed attempting to escape across the border elsewhere into West Germany.

Some of the photo images will live forever. On August 15, 1961 we see Conrad Schumann, the first border guard to escape, gracefully leaping over a tangled roll of barbed wire. On August 17, 1962, 18-year-old Peter Fechter bled to death while calling for help, shot down before he could reach sanctuary in the West.

Even as the world became ever more connected and sophisticated during the 1980s, this symbol of brutality and violence continued to divide Europe. So, too, did attempts at Republikflucht, or Republic Flight — a crime in East Germany — with arrests and imprisonments persisting up into 1989. As well as deaths. On February 5 20-year-old Chris Gueffroy was shot attempting to escape into West Berlin, the last East German murdered while seeking freedom.

But the East German state was rapidly running out of time.

Glasnost and perestroika gutted the totalitarian Soviet state throughout the mid to late 1980s. By late 1989 Hungary, Poland, and Czechoslovakia were all sliding out of Communism’s grip.

In fact, the Mauer Museum includes small exhibits on the freedom struggles in each of these nations. In all of them, courageous people risked their lives to demand liberty.

Soon demonstrations spiraled out of control in Leipzig, forcing the East German government to scramble to save itself. The authorities announced that they were relaxing border controls. When thousands of East Germans begin massing on the borders, the guards opened the gates on November 9, 1989.

The Wall had fallen. People danced on it and chipped pieces from it. It soon was torn down and the two Germanies agreed to reunify.

Checkpoint Charlie was formally demolished the following year. Now all that remains are the memories — and the Mauer Museum.

Of course, the struggle for human liberty did not end with the Berlin Wall. Tyrannies remain — the grotesque dictatorship of Kim Jong Il in North Korea, the oppressive rule of the mullahs in Iran, a bevy of African and South Asian dictatorships.

But to visit the Mauer Museum is to develop hope anew in the prospects for freedom. The point is not that human beings have suddenly become good or that evil has disappeared from the world. Rather, most human beings crave freedom. And the good guys sometimes win.