If my art has nothing to do with people's pain and sorrow, what is 'art' for?

The Chinese art world does not exist. In a society that restricts individual freedoms and violates human rights, anything that calls itself creative or independent is a pretence. It is impossible for a totalitarian society to create anything with passion and imagination.

The American experience influenced my understanding of individuality, basic human rights, freedom of expression and the rights and responsibilities of citizens.

When you have strict censorship of the internet, young students cannot receive a full education. Their view of the world is imbalanced. There can be no true discussion of the issues.

China and the U.S. are two societies with very different attitudes towards opinion and criticism. In China, I am constantly under surveillance. Even my slightest, most innocuous move can - and often is - censored by Chinese authorities.

Police in China can do whatever they want; after 81 days in arbitrary detention you clearly realise that they don't have to obey their own laws. In a society like this there is no negotiation, no discussion, except to tell you that power can crush you any time they want - not only you, your whole family and all people like you.

To the media, I have become a symbolic figure, critical of China. According to the government, I am a dangerous threat.

Now the British are coming. I think Cameron should ask the Chinese government not to make people 'disappear' or to jail them merely because they have different opinions.

China has not established the rule of law and if there is a power above the law there is no social justice. Everybody can be subjected to harm. I'm just a citizen: my life is equal in value to any other. But I'm thankful that when I lost my freedom so many people shared feelings and put such touching effort into helping me.

I think Chinese leadership is trying to tell the world they have another set of logic or reasoning or values which are different from yours. Of course, I don't think they believe that. It's just an argument that's made when you can't confront the truth and facts. They really want to maintain power.

As a person, I was born to give out my opinions. By giving out my opinions, I realize who I am. As long as I can communicate, I'm not so lonely. If I cannot travel, or do art, or have company, if they take away all my belongings, it doesn't matter at all.

To work in architecture you are so much involved with society, with politics, with bureaucrats. It's a very complicated process to do large projects. You start to see the society, how it functions, how it works. Then you have a lot of criticism about how it works.

Censorship is saying: 'I'm the one who says the last sentence. Whatever you say, the conclusion is mine.' But the internet is like a tree that is growing. The people will always have the last word - even if someone has a very weak, quiet voice. Such power will collapse because of a whisper.

People are always wondering if I am an artist or political activist or politician. Maybe I'll just clearly tell you: Whatever I do is not art. Let's say it is just objects or materials, movies or writing, but not art, OK?

I call on people to be 'obsessed citizens,' forever questioning and asking for accountability. That's the only chance we have today of a healthy and happy life.

The 'Bird's Nest' National Stadium, which I helped to conceive, is designed to embody the Olympic spirit of 'fair competition.' It tells people that freedom is possible but needs fairness, courage and strength.

I see the Beijing National Stadium as an architectural project. I accepted Herzog and De Meuron's invitation to collaborate on the design, and our proposal won the competition. From beginning to end, I stayed with the project. I am committed to fostering relationships between a city and its architecture.

Everyone wants an iPhone, but it would be impossible to design an iPhone in China because it's not a product; it's an understanding of human nature.