BEIJING • In a half-empty sub- division on the outskirts of China's capital, Yang Weidong is engaged in a quixotic struggle: to document China's soul through an epic series of video interviews.

Before embarking on his quest, Yang, 50, had a fairly conventional life. He grew up in Beijing and witnessed the 1989 Tiananmen incident, but had accommodated to the system.

He taught interior design and architecture at the prestigious Tsinghua University, had a lucrative private practice and ran a hip cafe in a trendy part of town.

Then, family tragedy struck.

His mother Xue Yinxian, who worked in the General Administration of Sports, came to prominence in the 1990s as a whistleblower, publicly saying she refused to dope Chinese athletes.

In 2007, on the eve of the Beijing Olympics, officials paid a visit to her home, warning her not to speak out about doping in China.

Her husband, who was convalescing from brain surgery, confronted the officials. The family says he was pushed by the officials (they say he fell) and injured his head, dying three months later.

His father's death unleashed something in Yang. Suddenly, he was consumed with one burning desire: to understand how China ended up with its authoritarian political and social system.

"After my father died, I couldn't figure out why it happened," he said during a visit to his home this summer. "I felt that society had problems and decided to find out why."

So began a remarkable effort to document what the Chinese think of their country's politics and society.

Since he started in March 2008, he has filmed 405 thinkers, artists, musicians, writers, historians - anyone who has thought hard about China's future. Some are government critics, others support the party.

"It's a survey of the state of mind of modern China," said Hong Kong book publisher Bao Pu. "His questions are related to the oppression his family faced."

At first, Yang said he was viewed with suspicion.

Then, in 2011, he published the first of six volumes of interviews in Hong Kong (because Chinese publishers refused, he said).

Covering 105 of his interviews, the volumes are titled For The Record, reflecting his goal: not to come up with grand conclusions, but to let people speak out on China's national condition, in the sort of debate that rarely happens in the country.

Yang uses the same 55 questions, most of them open-ended ("What does 'serve the people' mean to you?", "How do you understand labour?" and "How do you understand dread?").

His ultimate goal, he said, is to use the videos as part of a documentary.

However, he says he first wants to reach 500 interviews. Even then, he is not sure what to do with all the material. Copies have been sent abroad for safekeeping, he said.

The most memorable answers often come in response to his last question: "In the current society, what do you need most?"

The answers are sometimes banal, other times profound.

"I need fairness," said Xu Maomao, an actor.

"I need almost nothing now," said Chen Ershou, a famous geologist who has since died.

"I need freedom the most," said Chang Ping, an exiled columnist.

"I need time," said Yang Jisheng, a prominent journalist and historian.

"I need money," said Gao Yu, a dissident journalist who has since been placed under house arrest.

The project has put Yang and his family under severe pressure.

He and his wife Du Xing once owned two apartments, but had to sell them to pay for the film crew.

They now rent a slightly beaten- up apartment in a sub-division.

Yang is under a formal travel ban.

He was held for more than three months last year, but never charged, after he posted online a picture of himself naked in front of a government office protesting a decision preventing him and his mother from travelling to Hong Kong.

He said they were not allowed to travel because the International Olympic Committee was about to decide whether Beijing should win the 2022 Winter Olympics and did not want his mother to repeat allegations of doping. Beijing subsequently won the bid.

Having recently had two strokes, Yang's mother is less mobile. She is sure Chinese athletes are still doping.

"They prevented me from leaving, saying it would affect national security," she said.

"So, do you think they still dope?"

NEW YORK TIMES