Few filmmakers have been drawn to such delicate material as Ang Lee, and his new film Life of Pi is a supreme balancing act for one accustomed to walking on tightropes.
"I've been holding this anxiety for a long time. It's an expensive movie," says Lee. "It's really like the irrational number of pi. For a long time it felt that way - not making sense."
Life of Pi contains, Lee says, "all the nos" of filmmaking: child actors, live animals and oceans of water. It is an adaptation of Yann Martel's best-selling 2001 novel in which a deadly shipwreck maroons a boy (Suraj Sharma) on a lifeboat with a Bengal tiger.
Not only did filming such a tale involve considerable challenges, the story is ultimately a spiritual journey - and matters of God and faith are far from typical blockbuster fodder.
"Why do I dare, a Chinese director, do Jane Austen when I still speak pidgin English?" says Lee, referring to his 1995 film Sense and Sensibility. "It's still a leap of faith, you're taking a risk. Every movie is unknown. If it's known then no studio would lose money."
Lee was born and raised in Taiwan, where he initially pursued acting. In Taiwan, during the 1960s and 1970s artistic endeavour was considered a low profession, he says, and his father didn't approve. Ever since, patriarchs have been an important part of Lee's filmography. Responding to a comment that father figures - including one in Life of Pi - have often been focal points in his films, Lee corrects: "I think always.
"I never rebelled against him," he says. "The father figure is something I love, but also suffocate from and want to work against."
His first three films, all in Mandarin and about Chinese families, were followed by a distinct break with Sense and Sensibility, his Hollywood debut. But it was 1997's The Ice Storm, an adaptation of Rick Moody's novel about a Connecticut family's disaster in the swinging 70s,that Lee says changed his perception of filmmaking and set him on a new path.
"A movie is really provocation," says Lee. "It's not a message, it's not a statement. Before I thought: I have a story to tell, not even thinking of myself as an auteur. But that is a precious lesson to me, to take a step back - a respectful step back.
"Something about cinema, how it works in wonders, you just have to respect it," he adds. "You should never believe fully like you know."
Lee may be "a Zen master" as his Life of Pi star Suraj Sharma claims, but his tranquillity won't abide one thing: anyone who doesn't cherish the precious chance to make a movie. "If you don't give 100 per cent, I get mad," he says. It's enough of an all-consuming process that Lee doesn't contemplate his next film until he has seen through the present one.
He says: "I'm still surviving this one."