The one thing that people will come to know from the biography "Dr. Spock" is this: He was a lousy father and a bad husband.

Spock, the baby doctor who put the concept of empathy in child-rearing, was something else entirely at home.

He was demanding and critical ("Don't be a booby") of his two boys and distant from his grandchildren. And for the 48 years of his first marriage, he seemed to ignore his wife, the relationship growing into mutual rancor. After the 48 years, Jane Cheney Spock, who suffered alcoholism, breakdowns and much bitterness, was divorced by the great man. That was pretty much the end of her, and he moved on to a new life with a young love.

The charges in the 1960s that Spock was an advocate of permissiveness, who ruined an entire generation, were laughable to the doctor's two sons: Mike (born in 1933) and John (born in 1944). They knew him as a strict, critical, remote and unapproachable father. (Spock died March 15 at age 94.)

"The calm voice of Dr. Spock's book bore little resemblance to his blunt and condemning tones at home," Thomas Maier writes in his new biography, "Dr. Spock" (Harcourt Brace, $27). "Ben's comments were not terribly subtle or thoughtful,' recalls Mike. For a person who is as sophisticated and as measured in the way he writes, there's a quality to his relationships where he loads it on.' "

Of course it's sort of irresistible to read about the great baby doctor failing to follow his own advice. But it is hardly the whole of it.

Benjamin Spock was born in New Haven, Conn., in 1903. His mother was stern and moralistic, determined to "mold" her six children. His father was, in Spock's words, "grave but just." Mother believed in fresh air -- so much so that the children were put to bed on Cold Spring Street in an outdoor sleeping porch -- year-round.

Spock said he was a "mama's boy" and had to become a star Yale crew member and Olympic athlete before he started to feel like a regular guy. Along the way, he romanced and married Jane Cheney (of the Manchester, Conn., silk manufacturing family). He graduated first in his class from Columbia medical school, and while in New York in the 1930s, studied at the New York Psychoanalytic Institute.

He became the first to incorporate psychology (really Freudianism) with child-care advice. In this way, Maier notes, he gave parents an alternative to the crude, insensitive child-rearing practices of the past. The first Dr. Spock manual was published in 1946.

And it sounded good. How better to regard a newborn: As a friendly, engaging person ready to bloom? Or, a carrier of sin whose will must be broken? "Baby and Child Care" has sold 50 million copies and has been translated in more than 30 languages.

Problem is, parents ran with it -- right on overboard. That's one reason Spock unfairly was blamed for encouraging permissiveness. (The others were political.)

That Spock was unable to follow his own good advice does not diminish his work. The book stands on its own. It advocates a style of parenting that psychologists call "authoritative," which research proves most effective.

Spock, though, was a man of his time. That he was stern and remote with his children makes sense -- that is what he knew as a child. His parents were from another century.

When else but the mid-1970s, in Manhattan to boot, could such a respected figure divorce his debilitated wife of nearly 50 years? Shortly after his divorce, he married Mary Morgan, then in her thirties. She was a free spirit, perfect for the times: Morgan's cousin recalled her lack of inhibition to Maier: " Mary had on a crochet bikini and it was bothering her, so she took it off. She water-skied naked around the lake,' " as her preteen daughter, Ginger, watched, mortified.

Still, that romance came from his second, decades-long career as political activist, and his outrage at the Vietnam War was genuine.

Before his divorce, Spock, despite his natural resistance, submitted to family therapy, in which he got pounded by various relatives. But he stuck with it, trying to figure out the reasons for his shortcomings. And it seems he was unguarded with his biographer Maier, open about his failings.

That Spock could know principles intellectually, but emotionally be unable to use them, is simply mundane.