So, the Olympics are finally over. The world watched athletes perform wonders for a fortnight and then they watched para-athletes do the same.

Among them, Oscar Pistorius, a double amputee from South Africa, was rewarded with three Gold medals. First he defeated all comers in the 100m sprint, completing it in 11.17 seconds. Not bad at all, especially when you consider that he has no legs beneath the knee. Then he won the 200m and 400m competitions.

Standing on the podium would have undoubtedly been a great moment, but I have a feeling that Oscar would have had mixed emotions. He had run well, but in his mind he had been competing several weeks late. Oscar really wanted to compete in the first Olympics.

His application to the Olympic authorities to run in the main event created a considerable storm of legal and media interest. Was he enhanced, normal or disabled? The problem to resolve was whether the flexible carbon-fiber blades that complete his legs gave Oscar an unfair advantage over his competitors. After many rounds in the courts, the Olympic committee said that he could run in the main competition, but he then failed to achieve a qualifying time so didn’t make the cut.

Although he did not take part this time, he will try again, and in any case, Oscar will not be the only technology-equipped athlete who seeks to run on the main stage.

Now, everyone recognizes that we are a long way from the original dress sense in which ancient Greek athletes competed naked, in part to show that their victory was unaided by any technological tool. Today, engineers design everything from hair bands to running shorts, glasses to spiked shoes. No athlete chases down the track in bare feet, but shod in kit that minimizes the energy loss that occurs with each stride of the race.

On the face of it, the legal question was whether Oscar’s blades do a better job than other people’s feet and shoes.

Underneath, however, the issue was more complex. Sport’s regulations aim to set ‘level playing fields’. They try to create situations where everyone has equal chances of winning – where dedication, training and determination will lead to success. To do this, however, we need to define what a normal human is like. That way we can decide whether any proposed aids would bring individuals up to a normal level of capability, or enhance them.

The problem is that normal isn’t easy to define. Human beings come in a wide range of sorts and sizes. Our genetic heritage and developmental opportunities craft many different variations on the theme. On top of this, people who compete in sports often show extreme abilities – so extreme that they can beat all others. As a result, if you could define a ‘norm’ you would probably end up banning many current competitors.

Push the quest for definitions a little further and you soon find that it is difficult to define what it is to be a human – certainly in terms of any material definition. We share many of our physical features with other animals, and our capabilities from tool use to communication are part of the daily life of many species. This resonates with the thoughts of the writer of Genesis who shows just how similar humans and other animals are: they are made of the same ‘stuff’ – dust (Gen 2:7 & 2:19) and they are both given spirit (Gen 2:7 & 6:17 & 7:15).

From a Christian perspective, however, there is a difference. And that is God’s image. This is given to humans alone. It is not that God looks like us but that we have a role to play – a duty that rests on the fact that we are responsible for our actions both to God and to the rest of God’s creation. Now this is a spiritual, not a material definition.

All too often when we are faced with making decisions relating to human abilities and ethics we look to material answers as ways of deriving definitions. We expect to find a physical characteristic that we can measure, or a capability that we can assess. In reality, they will always fall short of anything definitive because they ignore our key spiritual component, the critical element that makes humans what and who we are. On this basis, Oscar is as normal as the person who crouches next to him in the blocks, feet or no feet.

Pete Moore is a science communicator who operates at the interface of science, medical technology and ethics. His latest book ‘Enhancing me – the hope or hype of human enhancement’ was published earlier this year by Wiley in association with The Science Museum and the Dana Centre.