Liam Neeson is the most dour of film stars. Even as Oskar Schindler you could see him straining to find the bonhomie and charm he needed to deal with his Nazi counterparts. But in Bill Condon's "Kinsey" he's found the perfect vehicle for his talent: earnest to a fault, blind to his or anyone else's needs, unaware of the implications of dispensing sexual information to a puritanical society. Watching the film we have the feeling that this could well be a documentary of Kinsey's life, and Neeson somehow the man himself brought back to life.

Condon's last film was "Gods and Monsters," the story of 1930s director James Whale's final days - a wickedly knowledgeable performance by Ian McKellan - remembering his homosexual life as a younger man and newly excited sexually by his gardener (Brendan Fraser). Here in "Kinsey" Condon takes advantage of Neeson's ability to show naivete, forthrightness and, occasionally, a sly understanding of himself as Alfred Kinsey, the man who could rightly claim that in the year 1949, when he first published "Sexual Behavior in the Human Male," he changed America's view of sex. Kinsey was the quintessential academician, a biologist whose career at Indiana University was built on the study of gall wasps (he collected more than one million specimens - one million!). Almost by accident he was given the chance to teach a course in human sexuality, though with the proviso that it be taught only to married faculty and graduate students. Appalled by the ignorance he and his wife Clara McMillan, or Mac (Laura Linney in a lovely, understated performance) brought to their own wedding night, he shocked the campus by his frankness in the course. And that gave him the idea to quantify American sexual practices through a rigorous academic study. He decided to start with men, creating a questionnaire and looking for a statistically significant one hundred thousand respondents. He trained his team and they all set out, first interviewing each other for practice.

The film flashes back to a repressed childhood under the thumb of a distant, forbidding father (John Lithgow, struggling to deepen the screenplay's portrait of a stereotype), and then follows the first halting steps in amassing the survey's data. As time goes on Kinsey himself begins exploring the byways that had titillated him but had never been tasted. He sleeps with his prize student, the bisexual Clyde Martin (Peter Sarsgaard), and even encourages Clyde and Mac to sleep together. As the first volume is published the Rockefeller Foundation, which had underwritten it, becomes queasy and wants to withdraw, and Indiana alumni are outraged.