Dog training philosophies go in cycles. Is today's lenient phase coming to an end?

A lot of professional dog trainers hate Cesar Millan, and not just because he's rich. Millan—star of the television show Dog Whisperer, best-selling author, and friend of Oprah —believes that dogs need a leader, that leader is you, and that they must be given this information by any means necessary. His emphasis on human domination leads him to recommend, in some cases, rather dramatic techniques such as growling at the dog and rolling her onto her back while staring angrily into her eyes.

Millan himself says, "I don't train dogs." What he means is that he corrects behavior problems that are, at times, quite serious. But in the hands of amateurs, his tough-love techniques can seem harsh. Not long ago, the American Veterinary Society of Animal Behavior issued a strongly worded manifesto against Millan's so-called "dominance theory." A 2006 New York Times op-ed headlined "Pack of Lies" referred to him as "a charming one-man wrecking ball."

Such reactions are less a comment on Millan himself than a reflection of the latest skirmish in the canine culture wars. Before Millan, the popular wisdom was that dogs are best trained by giving them treats for good behavior. Dominance was downplayed, physical corrections discouraged. But before that, pet owners were routinely taught to treat bad behavior with a yank on the leash or a chain looped around the dog's neck. Food treats were for humans. Before that, dogs were often viewed more as livestock than four-legged friends.

Like T-shirts and child-rearing, dog training philosophies go through generational swings from loose to tight and back again. In Raising America, author (and Slate's book editor) Ann Hulbert reminds us that expert wisdom in the 1920s was to withhold affection from children, and a generation later, to pour it on with a ladle. By the 1990s, there was a call for a return to stricter parenting. Likewise with dogs: Millan and his followers are just bringing back some old-fashioned values.

How old-fashioned?

For two millenniums, from Ancient Rome through the 19^th century, it was generally believed that dogs—like horses and, well, children—had a wild spirit that needed to be "broken." In the 1890s, T.S. Hammond, author of Practical Dog Training, lamented that his fellow trainers believed that "all knowledge that is not beaten into a dog is worthless for all practical purposes."

At the same time, breeders in Europe and North America were beginning to organize, anti-cruelty societies were forming, and training began to be approached more scientifically. "Train your dog" first became a well-known slogan during the Great Depression. By the 1930s, a pair of New York-based poodle fanciers named Helene Whitehouse Walker and Blanche Saunders toured the country in a wagon, visiting breeders' clubs and evangelizing obedience as a sport on par with tracking and agility. Saunders went on to become the Cesar Millan of her era. She published the first modern guidebook for dog trainers, Training You To Train Your Dog. Saunders' basic methods were more or less standard into the 1970s. No treats, but it's OK to praise. Look for the dog to do something wrong and jerk on a choke chain around her neck. Use physical guidance to teach things like sits.

Animal behaviorists call methods like the choke chain—correcting errors with painful consequences—punishment. * The most successful of the negative gurus was William Koehler, head of animal training for Walt Disney Studios and the guy behind the dog actors in Swiss Family Robinson and Incredible Journey. His book, The Koehler Method of Dog Training, first published in 1962, was the best-selling obedience title in the United States for two decades.

Today, certain passages in Koehler's book can make for difficult reading. "Hold [the dog] suspended until he has neither the strength nor inclination to renew the fight," he writes at one point. "Once lowered he will probably stagger loop-legged for a few steps, vomit once or twice, and roll over on his side. But do not let it alarm you." We'll try.

Koehler was an effective trainer, as anyone can attest who has watched the canine thespians execute the tour de force that is Incredible Journey. But he was not sentimental. He believed in nipping problems in the bud by bringing the pain. Training was a battle of wills, and it was you or the dog. He believed it was hurtful to our best friend to be too kind—that the greatest of all physical and psychological cruelties was "under-correction."