Of horses and men - on 'Nova'

''Breed the best to the best . . . and hope for the best'' has become the unofficial motto of the multinational, multibillion-dollar horse-racing industry. You can breed a thoroughbred but you can never be sure he'll be a winner.

What is a sure winner, however, is A Magic Way of Going: The Story of Thoroughbreds (PBS, Tuesday, Nov. 15, 8-9 p.m., check local listings), ''Nova's'' startlingly beautiful and slightly magical tale of the world's enchantment with equus.

With more than 500,000 registered thoroughbred horses in the world, with owners sometimes clamoring to pay more than $100,000 as a stud fee for a champion such as Secretariat or Northern Dancer, the business of thoroughbreds has come a long way from the days in the 1790s, when the registry of the offspring of certain Arabian stallions and British brood mares first began.

''A Magic Way,'' filmed in Canada, the United States, Britain, and Ireland by the Canadian Broadcasting Company, with John Bassett producing and directing, has chosen an ambivalent task for itself. On one hand, it idealizes the aristocratic bearing, the eloquence, strength, and awesome beauty of the horse, while on the other it takes a very passive look at the mechanics of breeding and horse racing, which tend to demean the natural characteristics it is eulogizing.

It was upsetting to me when a breeding expert referred to the horse as ''one of the greatest aerobic machines in the animal kingdom.'' It seemed degrading to reduce this magnificent creature to muscles and oxygen. And that is perhaps what becomes slightly distorted in this engrossing, if one-track-minded, film. The wonder of horses is a natural wonder . . . and by overanalyzing, distilling, and synthesizing those wonders, don't we run the risk of losing instinctive perspective?

I found it a bit ironic to present a cinematic paean to the dignity of the horse, full of magnificent shots of boundless animals running freely, and then show him confined, shackled, being broken for the bridle and saddle, trained to obey the orders of a trainer and jockey - and all this almost solely to serve the interests of competitive racing for the pleasure of a gambling public.

In addition, one of the breeding experts states that the intensive breeding seems to have resulted in a kind of genetic plateau. This should give pause to scientists involved in genetic engineering of humans.

Credit John Mansfield, executive producer of WGBH's ''Nova'' (still television's prime science show), with spotting this breathtakingly beautiful and informative Canadian film and bringing it to the attention of the American public. If it raises philosophical questions in the minds of viewers, all the better.