Looking back on the past 100 years, Elie Wiesel could come up with only one conclusion last week.

"Something was wrong with this century," he said.

For him, the murder of six million Jews at the hands of the Nazis still outweighs the collective achievements of this timespan.

"How is it possible that it happened?" he said, repeating the unanswerable question that millions continue to ask about the Holocaust.

More than 1,600 Bay Area residents came to hear the renowned Holocaust survivor and Nobel Peace Prize winner at San Francisco's Congregation Emanu-El on May 9. The event was sponsored by the Jewish Community Center of San Francisco and supported in part by the Jewish Bulletin to mark the 100th anniversary of Bay Area Jewish journalism.

In an hourlong appearance that began and ended with standing ovations, Wiesel combed through the events of the 20th century with a philosopher's intensity and turned repeatedly to a theme of despair vs. hope. Dressed in a charcoal-gray suit and wearing a black kippah atop his bushy dark hair, Wiesel started by saying he'd been asked to discuss what lies ahead.

"I must confess — being in a holy place — I don't know the answer," quipped a tan and relaxed Wiesel, drawing a burst of chuckles from his audience.

But Wiesel did look back — at a century in which totalitarian regimes engineered the humiliation, torment and annihilation of millions.

While he acknowledged that Jews suffered through the Crusades, the Inquisition and Russia's pogroms, Wiesel insisted that Jews never had become "abstractions" until the Nazis came to power.

"Never before have our people — any people — been reduced to objects," he said.

But the 20th century offered glimpses of hope as well, he said. Commending the Allied forces for defeating Nazi Germany, he also blessed the birth of Israel, the end of apartheid and the fall of communism. He marveled at the emigration of Soviet Jews. He lauded this century's advances in science and medicine.

But even these triumphs are tainted, he said. Calling Israel a source of "joy and gratitude," Wiesel reminded the audience of the persistent terrorism and wars that have killed so many in the Jewish state.

"How can we say our joy is total?" he asked.

Wiesel questioned even the medical advances that now allow human beings to live well past their 60s.

"We are doing everything to prolong life. However, what are we doing when life is being extended? We discard [the elderly]," he said. "We don't want to see them. At best, we send them to Florida."

At age 67, Wiesel is hardly ready to be discarded. After writing more than 35 books, the Boston University humanities professor recently released the first volume of his memoirs, titled "All Rivers Run to the Sea."

His first book, published nearly 40 years ago, is arguably his best-known work. In "Night," Wiesel recounted his years as a concentration-camp prisoner.

Those years continue to torture his soul.

"Nobody comes to peace after such an experience," he told the crowd at Emanu-El.

Nonetheless, Wiesel repeatedly declared that remembering the past should not lead only to despondency.

"I don't like to teach despair," he said. "I always like…to leave one door open."

This philosophy enables him to face not only the past but also the future.

Wiesel, who lived through Auschwitz and Buchenwald, pins his hopes on survivors' children and friends, as well as on anyone who studies the Holocaust or hears a survivor's story. He urges everyone to take on the burden of remembrance.

"We are asked often, `What happens when the survivors are gone?'" he said.

He told the audience to remember that, from now on, "you yourselves are witnesses."

The longtime activist, who has won international recognition for his human rights efforts in countries as diverse as Nicaragua, Cambodia, South Africa, Argentina and Bosnia, told why he has worked so hard to end suffering.

"Always it was linked to children," he said. While others may be able to endure the fact that so many youngsters still die from disease, hunger and warfare, "I cannot."

He appealed to audience members to reach out to other communities, other religions, other races.

Jews, of all people, know that an individual can fight evil, he said. Even under the Nazi terror, individuals opened their doors, offered documents, helped a child.

Today, survivors and their families remember those individuals with "infinite gratitude."

His experiences have taught him that "indifference is the worst," he said. "Indifference or silence never helped the victim."