LONDON — First, you start with the incredible, mesmerizing sight of it. Later, you can talk about the results and the controversy and the story.
For now, you look in wonder as the man without feet speeds around an Olympic track.
You cannot look away. To watch Oscar Pistorius, the "Blade Runner," in action is like watching something out of a science-fiction movie. Pistorius flashes around the track, passing one competitor, then another, the bottom of his legs churning like the wheels of a paddleboat. He finishes second in his 400-meter heat, and he raises his arms in triumph, and his smile is as bright as the British morning sun.
But you do not look at his arms or at his smile. You look at his legs.
In particular, you look at the parts that are not there.
Below the knees of Pistorius, 25, are prosthetic legs made of carbon fiber. They jut from the back of each knee, curving slightly backward and then thrusting forward with feet like a large spatula. It seems as if it would be impossible to balance upon them, let alone run a world-class time.
Has there ever been a vision as inspiring as Pistorius racing around the track on artificial limbs? Has there ever been an athlete who has overcome so much or one who can inspire so many?
And while we are at it, has there ever been a sillier question than this one: Hey, Oscar, do your legs give you an advantage?
Perhaps there is something about Pistorius that makes it hard for people to believe what they see. There are people — including former Olympic 400-meter champion Michael Johnson — who believe the composition of the blades gives Pistorius an advantage.
It was back in 2007 when scientists in Cologne, Germany, decided that Pistorius had an advantage. According to their measurements, the legs allowed Pistorius to run the same speed as others without using as much energy. However, the study didn't consider Pistorius' disadvantages, such as his slow starts. In January 2008, he was banned from running against able-bodied competition. He appealed. A few months later, Pistorius was cleared to race.
An advantage? Just asking, but does anyone want to swap?
It's a silly notion. Paralympians have been running on the same prosthetics — the Flex-Foot Cheetah — as Pistorius since 1996. If they gave a runner an advantage, wouldn't others runners using them have been breaking records for years? Wouldn't the Olympics have been filled with such runners by now? These aren't bionic legs, for crying out loud.
If Pistorius has an advantage, it has nothing to do with his legs. It has to do with his spirit. It has to do with a small boy running to prove to his friends that he could keep up, that he could do anything. It has to do with an athlete who could not be contained by the Paralympics.
The Olympics need athletes such as Pistorius. For that matter, the world does, too. Can you imagine watching him through the eyes of disabled children? Can you imagine how many more dreams must seem possible?
A Brit named William Swift has the answer. Swift lost his right leg in a motorcycle accident in 2005. He knows all about obstacles.
"What it demonstrates is that it doesn't matter what adversities you face," Swift said Saturday on his way into Olympic Stadium. "You can exceed all the expectations of normal able-bodied people. When you see what he has done, you think anything is possible. I'll be cheering him on louder than pretty much everyone else there."
Others will cheer, too, including most of his competitors. Pistorius is not a medal threat in the 400, at least not yet, but he seems to be well-liked by other runners.
"He inspires me," said American Bryshon Nellum. "When something like that happens, some people would give up. For him to continue to run against people with legs … it's unbelievable. It's amazing."
To a point, Nellum, 23, can relate. When he was 19, he was the victim of a drive-by shooting. A shotgun blast hit his legs, and he needed surgery, and he spent time in a wheelchair.
"To not have your legs … we take certain things for granted," he said.
Pistorius seems to like the part about being a role model. He speaks quickly, he grins a lot, and he uses the word "blessed" to describe himself.
How can he not? He stood in his lane Saturday morning, trying to focus through the joy of performing in the Olympics.
This is the kid who was not allowed to feel sorry for himself. He had been born without fibulas in both legs, and doctors thought it would be better to amputate his legs below the knees before he learned how to walk. He never ran on real legs.
"My mother said to us one morning, 'Carl (Oscar's brother), you put on your shoes, and Oscar, you put on your prosthetic legs, and I don't want to hear any more about it,' " Pistorius said. "I grew up not really thinking I had a disability. I grew up thinking I had different shoes."
Another time, when two bullies were picking on Pistorius, his father made his son take care of the situation himself.
It was that kind of toughness that led Pistorius here Saturday morning. He stood in his lane, trying harder to focus than to reflect on his journey. A man in the stands yelled to him, "Hey, you sexy beauty." The South Africans' flags waved. The crowd cheered his name.
"It's such a whirlwind of emotions," Pistorius said in the media zone after advancing to the semifinals, sweatpants covering his prosthetic legs, sneakers at the bottom of them. "You want to take in the occasion and say, 'Wow, I'm at the Olympics.' At the same point, you want to take it seriously. All these things go through your mind. You have the self-confidence to do well, but you've also got nature making you doubt."
For Pistorius, the doubts are over. He made it to the Olympics. The world watched him run.
This time, the advantage belonged to the world.
Gary Shelton is in London to cover his 10th Olympic Games for the Times. Follow his experiences on Twitter at @Gary_Shelton, through his photo feed #londongary on Instagram, and through his daily columns in the Times.