THE Twitter account of Ai Weiwei, China's foremost artist-activist, fell silent when he was arrested on April 3rd. Chinese state media suggest that he is guilty of "economic crimes" and a bevy of other reputation-killers such as plagiarism and being "erratic." But his imprisonment is clearly a means of shutting him up. A forceful advocate of democracy and free speech, Mr Ai used his blog to confront the fictions of government propaganda. With belligerent conviction, he railed against the inhumanity of a regime with no respect for the truth."Twitter is most suitable for me. In the Chinese language, 140 characters is a novella," says Mr Ai in an interview at the back of " Ai Weiwei's Blog ", a collection of over a hundred translated pieces culled from over 2,700 posts. Mr Ai's father, Ai Qing, was a poet who was deemed an enemy of the state in 1957, rehabilitated only when the Cultural Revolution died down in 1976. But Mr Ai had written very little himself. In fact, the visual artist barely knew how to type when he was invited by Sina, China's largest internet portal, to write a blog for their website.A proponent of simple, authentic architecture, not fancy forms for form's sake, Mr Ai has overseen some 70 architectural projects, and was a consultant on Herzog & de Meuron's "Bird's Nest" stadium for the Beijing Olympics. Some of Mr Ai's most memorable writings weave personal history with political and aesthetic principles. For example, his "earliest experience with architecture" took place when his father was sentenced to hard labour and re-education and the family was forced to live in an earthen pit in Xinjiang. "In political circumstances like those, living underground can provide an incredible feeling of security," he writes. "In the winter it was warm, in the summer it was cool. Its walls were linked with America." Mr Ai's father raised the ceilings of this home by burrowing down another 20 centimetres, and he dug out a bookshelf that eight-year-old Weiwei considered "the best". For these reasons, concludes the artist, "I don't believe in ideal architecture."In 2007 Mr Ai integrated his blog into his art when he was creating an epic performance titled "Fairytale". Through the internet, he recruited 1,001 Chinese people who had never been to Europe to wander around the small town of Kassel Germany during Documenta, a prestigious exhibition that takes place every five years. Mr Ai wanted to change their lives. The artist had spent 12 years in New York City; he understood the horizon-expanding powers of being abroad.The bulk of Mr Ai's writings preach the importance of various human rights to a Chinese audience who is not yet converted. On the eve of the 20-year anniversary of Tiananmen Square, he wrote with elegiac irony: "Let us forget June Fourth, forget that day with no special significance... People with no freedom of speech, no freedom of the press and no right to vote aren't human, and they don't need a memory… Forget those soldiers firing on civilians... the city and the square that didn't shed tears. Forget the endless lies, the leaders in power who insist that everyone must forget, forget their weakness, wickedness, and ineptitude… For our own survival, let us forget."When it comes to the West, Mr Ai is a fan of Andy Warhol, Barack Obama and Hillary Clinton. He is not so fond of Nancy Pelosi, an American congresswoman. After hearing her "mumbles" on human rights at the American Embassy in Beijing in May 2009, he declared: "I have finally witnessed the amount of money that could turn a once crafty heroine into an obsequious, culpable old bag." After her speech, he found plainclothes policemen waiting for him at his studio-home. They didn't have their police identification, so he called 110 (the equivalent of 911) and what followed was, as he puts it, "an absurdist novel gone wrong."Mr Ai has had many confrontations with the police, including one incident in Sichuan province where he was so badly beaten that he developed a cerebral haemorrhage that required surgery. Since his Sina.com blog was censored in May 2009, his existence has been erased from the digital domain on the Mainland. "Words can be deleted but the facts won't be deleted along with them," he affirms on Twitter via a VPN that allows him to jump over the Great Firewall . "No matter what happens, nothing can prevent the historical process by which society demands freedom and democracy," he asserts, adding, "What can they do to me?"Indeed, if anyone can survive unjust imprisonment, it is Mr Ai. In an interview with The Economist before he was incarcerated, he said that his father did not want him to be an artist for fear that he would suffer. "But I became an artist because, even under pressure, my father still had somewhere nobody could touch," he explained. "Even when the whole world was dark, there was something warm in his heart."

"Ai Weiwei's Blog: Writings, Interviews and Digital Rants, 2006-2009" (MIT Press), edited and translated by Lee Ambrozy

Picture credit: A self-portrait (top) taken during Ai Weiwei's arrest in Sichuan province (before he was beaten); it's 5am and he is in a hotel elevator with a policeman and a fellow activist. On April 9th Cai Yuan, an artist, and Ma Jian, a writer, staged a protest at Tate Modern by putting "Free Ai Weiwei" flyers all over his "Sunflower Seeds" installation; photo: Cai Yuan