Oscar Pistorius, also known as “Blade Runner,’ is a remarkable South African athlete who competes as a sprinter despite missing the lower half of both legs. Born without fibulas, he was 11 months old when his legs were amputated below the knee. Now he runs on specially designed prosthetics made of carbon fiber, and has been fighting to gain eligibility to compete in the Olympics. The International Association of Athletics Federations, however, has banned him, saying that his “blades” give him an advantage over other runners. Advocates for the handicapped are challenging the ruling, claiming it is unfair to stop Pistorius from competing with the body he has, carbon fibers and all. Archers and marksmen with contact lenses are allowed to compete against those with unenhanced vision. Why should this be different?

The controversy retraces many of the same arguments as the saga of Tatiana McFadden [“Wheelchair Racing Ethics,” 3/28/07], a young Maryland woman who “sprints” while confined to a wheelchair. She and her family have been fighting in the courts to allow her to compete in state high school track and field meets, but cannot overcome the basic problem that a running a race on wheels and running a race of legs are two different things. Nobody is saying that it is easy for Tatiana to propel herself using arms and wheels, just that it is sufficiently different that there can be no fair competition between her and runners who do it the old fashioned way — on their feet. Pistorius at least has to use his legs, but his physical adaptations come a lot closer to suggesting a bionic man. An independent study commissioned by the IAAF concluded that

(1) “Pistorius was able to run with his prosthetic blades at the same speed as the able-bodied sprinters with about 25 per cent less energy expenditure”;

(2) “…the … returned energy from the prosthetic blade is close to three times higher than with the human ankle joint in maximum sprinting”; and

(3) “…the mechanical advantage of the blade in relation to the healthy ankle joint of a two-legged athlete is higher than 30 per cent.”

The study was overkill; the decision to exclude Pistorius made logical and ethical sense because he was competing in a human athletic event while relying significantly on a non-human body part. This could be an absolute rule that even Kant would approve of. If non-human body parts are allowed to substitute for flesh and blood, it opens the door for all sorts of intentional mutilations by aspiring athletes, who, as we have seen, are more than willing to risk their health, longevity, human relationships, sanity and comfort if it means excelling in their chosen sport. Watch boxers get their lower arms surgically removed so they can be replaced with chin-shattering titanium clubs! See basketball players get their legs extended with steel shinbones! Swimmers with surgically created webbed feet and fingers!

It is not, as some vocal critics have argued, a superseding ethical priority to allow athletes with disabilities to make use of all means possible so they can have access to high level competition. Most of us are born with a handicap that prevents us from competing in the Olympics — the handicap is called “not enough ability.” Sometimes the lack of ability is genetic, sometimes it derives from the fact that we were brought up in a home full of couch potatoes, and sometimes it’s because we broke an arm falling out of a tree house and can’t throw a ball right anymore. All too bad, and unfair in the way that life has always been unfair, but not sufficient to overcome the necessity of drawing a sensible and coherent line to ban the nine-foot tall basketball player with implanted stilts for legs or the gilled swimmer.

Drawing a clear line doesn’t mean that it will always be clear on which side of it a particular case falls. Gino De Keersmaeker, a Belgian discus thrower, has one real leg, and one prosthetic. Does the prosthetic leg give him an advantage, or simply allow him to compete at all? It’s a tougher call, but even though you can’t draw a line that is so clear and perfect that it will resolve every problem, lines are still worth drawing.

Lying ahead are other lines that must be drawn. How do we regard contact lenses that give baseball players extraordinary vision…or just make everything clearer? If drugs that make players stronger and bigger are banned, what about drugs that can make a football quarterback smarter? And most perplexing of all, what do we do when science can produce unnatural athletes naturally, by genetic manipulation? Is a nine-foot tall basketball player created by gene-splicing more acceptable than one who uses prosthetics? If science could breed the eight-armed ping-pong player depicted in the idiotic film “Balls of Fury,” should he be allowed to compete against players with just two arms?

All good questions, and we will get to them in due time. For now, however, the verdict on “Bladerunner” has to be a respectful “no.” The ethical line is fair and sensible: human races on human feet. We shouldn’t be afraid to draw it.