IF IT LACKS a certain fuzzy warmth, "Kinsey" makes up for the shortfall with spirited and (for a commercial movie) amazingly candid vigor. It's an alert, lively movie with a crackling performance by Liam Neeson as Alfred Kinsey -- the sexual behavior scientist whose "Sexual Behavior in the Human Male" and "Sexual Behavior in the Human Female" ignited a firestorm of controversy in the postwar years.

Even today, Kinsey's findings attract heated excoriation from conservative groups who see a direct connection between the researcher's findings and a number of perceived social outrages, including government-funded sexual education, encouragement of masturbation, and premarital sexual experimentation, free-and-easy condom dispensation and society's increasing acceptance of homosexuality. And recently, the Concerned Women for America has taken on "Kinsey" for not showing that Kinsey also interviewed pedophiles and concluded from those conversations that children can be sexual at extremely early ages. This subject is nowhere to be found in the movie.

What can be found in "Kinsey" is a convincing picture of an America semiconsciously cowered in fear and ignorance about sexuality. In the 1940s, Indiana University biology professor Kinsey comes to realize that only single-minded zeal can break down these inhibitions and irrationality. He learns this after a series of experiences: a life spent with a sanctimonious, priggish father (John Lithgow); such prohibitive literature as the Boy Scouts handbook; and an uncomfortable, dissatisfying first night with his new bride, Clara McMillen (Laura Linney).

In a world where masturbation and homosexuality are considered the road straight to damnation, where some believe oral sex can lead to pregnancy and where even "normal" sexual relations between husband and wife are fraught with doubt, inexperience and lack of creativity, Kinsey finds his true calling. He must help everyone somehow. But what can he do? His experience consists of 20 years of bookish academe, including a tome or two about the mysteries of the gall wasp. He's a bug geek.

Kinsey starts with a course about sexuality in marriage. It's an enormously popular class because of Kinsey's scientific forthrightness, not to mention graphic pictures and slides. Buoyed by his success, Kinsey secures the moral support of his university president (Oliver Platt) and funding from the Rockefeller Foundation and embarks on a study of men's sexual habits. It takes years of brutally frank, one-on-one conversations. But with the help of dedicated assistants, including Clyde Martin (Peter Sarsgaard), Paul Gebhard (Timothy Hutton) and Wardell Pomeroy (Chris O'Donnell), Kinsey completes the study, "Sexual Behavior in the Human Male."

It's a cultural breakthrough: People are suddenly asked to reassess themselves in sexual, even zoological terms. Predictably, the book (and its follow-up on female sexuality) triggers controversy from moral conservatives. There is pressure on the university and the Rockefeller Foundation to withdraw support, and, very soon, Kinsey finds himself a pariah in many circles. He spends his last years, before his death in 1956, still dedicated to his work, desperately seeking more funding.

While he's advocating freshness, freedom and sense in the public arena, Kinsey is mired in moral questions at home. He explores his homosexual side with one of his assistants, much to the shock of Clara, and he encourages sexual experimentation among his followers. Is he the liberated man he asks others to be? What exactly is liberation? Kinsey finds himself caught in the endless conundrum of life.

Writer-director Bill Condon, who made the underappreciated "Gods and Monsters," has created a supple, potent work that advocates the kind of compassion and diversity that, in some corners of society, remain as marginalized as they were in the 1940s. It's an important work, bigger than the story it tells.

Linney is affecting as Kinsey's wife, deeply in love with him but having to deal with the tyranny of his mission. This film closes a great year for the actress; she was equally persuasive in the movie "P.S."

As Kinsey, Neeson's as memorable as he was playing Oskar Schindler in "Schindler's List." Like Schindler, he's a loner who learns how to influence society by applying its own methods (in this case, scientific study with foundation funding and university support) to change things from within. Large-framed and sporting an almost comical spike of hair, he makes a compelling, soft-eyed giant. He's a pioneer of sorts, completely dedicated to the task of smashing his head against the Puritan wall until something gives. In "Kinsey," he dislodges enough bricks for a piercing shaft of light to break through. As this movie shows, we're still squinting in that brightness today.

KINSEY (R, 118 minutes) -- Contains pervasive sexual content, including nudity, sexual scenes, graphic images and frank discussion of sexual behavior. Area theaters.

Liam Neeson in "Kinsey," which explores the life and psyche of the pioneering sex researcher.