Much more than LSD and The Beatles, the father of the sexual revolution that inflamed campuses in the 1960s was a man who, if this film does him justice, could have been the prototype for Mr. Spock. His first book on the subject, "Sexual Behavior and the Human Male," published in 1948, was opportunistically dubbed by the press an atom bomb. The idea that men went foraging for forbidden fruit more often than previously thought sent shock waves through postwar American society. But his follow-up, which told of sisters and grandmothers entangled in extramarital lesbian affairs, nearly had the villagers rioting at the mad scientist's gate.

Investigating something as messy as sex was not for the weak-hearted, and "Kinsey" is unflinching, though it largely hurries through the public furor. The film deals with Kinsey's infamous interview of a man claiming to have had sex with hundreds of young children, but curiously omits the public's reaction. Condon concentrates on the man, born in Hoboken in 1894 to a stern preacher (John Lithgow, reprising his role in "Footloose"). The era, we learn, was woefully and willfully ignorant about sex. The subject was one of the last to get a thorough going-over by science. Young men and women arrived at their marriage vows without much more than an inkling of what came next. In "Kinsey," the lucky ones believe silly rumors, like that oral stimulation leads to pregnancy. The unlucky ones still believe in the stork.

"Kinsey" plays up the purity for plenty of comic value, but it almost re-creates academic life at the university to the point of creepiness. Slide shows of engorged genitals and films of masturbating elderly women mortified students, and may even disturb contemporary observers. But listening to Kinsey's wife (Laura Linney) and colleagues call him Prak — an affectionate but unpoetic acronym for Pr(ofessor) A(lbert) K(insey) — is an embarrassment no one should have to sit through. Still, Condon deserves credit for transforming his chiseled lead actor (Liam Neeson) into Kinsey's geeky figure. With that grating nickname, his bad sweaters and a haircut that looks torn from a rug, Neeson struts around like some kind of prehistoric terrestrial bird, one his character would definitely want to study.

The enclave of handsome young research assistants Kinsey assembled offer much-needed visual relief, with adequate portrayals from Peter Sarsgaard, Chris O'Donnell and Timothy Hutton. Sarsgaard, a supple blend of character actor and leading man, is especially good as a sort of hands-on test subject for Kinsey's healthy fascination with — to put it scientifically — gender variation. (Put a blonde wig over those puppy-dog eyes and he'd be Chloe Sevigny.) It may be tough for some in the audience to see Neeson and Sarsgaard lip-locked in muscular embrace, but what sustains this film is the same thing that sustained its subject: a dogged determination to get at the facts, no matter how uncomfortable they may be. "Kinsey" is an uncommonly realistic and pleasing portrait of a man of science — a man who, whether it's nice to point out or not, could be downright weird. Whether plumbing gay clubs for data or dealing permissively with infidelity, he seems as odd to the world now as he did then. Condon serves him well by being fearless. *** S