Power and popularity of China's Communist Party
In the grounds of what used to be a church school in Beijing, the Chinese Communist Party has set up an altogether different educational institution. It is still a school, but its aim has changed. Here they worship the party, not God.
This school is part of a system of control that has kept the communists in power in this huge nation for more than half a century.
As it celebrates its 90th anniversary this week, the party seems as strong as it ever has, sitting on top of a country that is getting more powerful by the day.
But there are problems that make the party surprisingly vulnerable despite its economic success.
It tolerates little dissent and ultimately maintains control through a system that uses force to suppress those who disagree with its rule.
Some say this cannot continue and the party will have to reform if it is to survive.
The Chinese Communist Party is all powerful. It decides the policies, the government carries them out. Its reach extends into all aspects of life.
With no apparent sense of irony, the party recently announced it would supervise the polls organised to select local government officials - to ensure "fair elections".
The Beijing Communist Party School is just one example of the control it exerts.
Senior party members have to undergo three months of training at schools like this every three years to make sure they understand the organisation's latest ideas.
They then take those back to their jobs and implement them.
One of those attending a recent lecture at the school was Chu Xiaolin, the deputy-editor of the Beijing Daily newspaper.
"We don't understand everything about society - so the party school provides us with experts from all walks of life," she said.
"They give us the latest information. This allows us to deal with problems in a more comprehensive manner."
The class she attended outlined the challenges the party faces from the internet.
At another lecture at another school, party members were studying Mao Zedong, the communists' most revered revolutionary leader.
Under Chairman Mao's leadership tens of millions of people died, but party members do not study him to learn about his mistakes - they are taught about his political skill.
The professor giving the lecture, Liu Feng, said the former leader understood how to relate to people, and that is something party members need to know.
"If the Chinese Communist Party is to rule, it has to have legitimacy. We need people's approval and support," said Prof Liu.
But the party has no plans to seek that approval by introducing democratic elections, even though there is debate among senior leaders about political reform.
Zhou Chunming, an administrator at the Beijing party school, said the communists had no need to change the system because most people supported it.
He added: "Democracies have their problems too. Why did Hitler come to power in Germany? It's because of democracy."
China is, in fact, currently engaged in the biggest crackdown on dissent in recent years. This is the darker side of party's control over society.
The party-directed government now spends more money on internal security than on national defence, locking up Tibetans, pro-democracy activists and people forced from their homes for redevelopment - anyone who threatens its rule.
In recent weeks it has deployed the army-controlled People's Armed Police to quell dissenting Mongolians in the north and rioting migrant workers in the south.
That does not mean the Communist Party is not prepared to change. The party has survived so long precisely because it has adapted.
Thirty years ago it began abandoning communism for capitalism, leading to the economic boom that will probably make China the world's richest country sometime in the middle of this century.
Sidney Rittenberg, one of just a handful of Americans to join the Chinese Communist Party, said it would have to change again if it is to survive.
"We'll get to a certain point where people will no longer be willing to have an advanced market economy and a backward political system," said the 89-year-old, who knew Mao.
The Chinese Communist Party is a secretive organisation - members promise to keep its secrets in their pledge of allegiance when they join.
In an interview with the BBC, party member Zhao Tong telephoned the head of his party cell just before our chat to check it was all right to talk.
"I'll report back to you afterwards," the 33-year-old software engineer told his leader after getting the necessary approval.
This secrecy makes it difficult to predict how the party will change in the future.
But at the moment it remains in firm control in China - and appears to have the support of most people, many of whom remember the chaos this country has endured in the past.
"The key to having a good knowledge about China lies in a better knowledge of the Communist Party," Ai Ping, vice-director of the party's international department, recently told foreign journalists.
In many leaders' minds, China and the party are often fused together as one idea.
This is a deliberate exaggeration, but one that the communists will be hoping to maintain for many years to come.