In the past week, two astonishing face transplant stories have been in the news. Richard Norris of Hillsville, Virginia, was shot in the face in 1997 and lost his nose, lips and most movement in his mouth. On 27 March, surgeons from the University of Maryland Medical Centre detailed what is widely thought to be the most comprehensive face transplant ever, while revealing Norris to the world. The before and after pictures were stunning.

Yesterday, independent.co.uk carried a very moving news clip of a press conference given by Dallas Wiens, right, another American, who was terribly burnt and blinded in a freak accident while painting a church. "By all accounts Dallas should not have survived the devastating injury that took his face", said Dr Bohdan Pomahac, his plastic surgeon. "But he did." Mr Wiens described how he cried when his four-year-old daughter, who he will never see again, kissed him for the first time in years.

When your pride in humanity is shaken – by war, crime, Samantha Brick, George Osborne, BBC3, and other such horrors – look to science, the engine of progress. Because our society has spent three decades living beyond our means, and created illusory economic growth which mostly favours the rich, progress is currently unfashionable in the West. That is why it has never needed defending more.

There are those, like the magnificent polemicist (I stop short of calling him a philosopher) John Gray, who are applauded when they tell us progress is a delusion, that the growing knowledge given by science will only be mobilised for conflicting ends, and that we now seek in science little more than salvation from ourselves.

But those who buy this argument fail to distinguish between two aspects of human progress. The first is moral; the second, material. Because moral knowledge isn't cumulative, like scientific knowledge, it can be lost just as easily as it has been gained. There has, overall, been great moral advancement among humanity, usually where religion has lost its monopoly on organised violence, and given way to a system of rights; but we will always retain the capacity to do wrong. Science cannot erase human error.

Yet the gains in knowledge made by science can be used for a most noble material end, which is to reduce human suffering. Across the world, the cumulative efforts of generations of scientists are achieving that on an inspirational and life-affirming scale.

Science provides the most exciting evidence of the possibility of progress. Those who believe that the latter is merely the latest secular myth – "that vast, moth-eaten musical brocade, created to pretend we never die" as Larkin said of religion in Aubade – should be acquainted with Norris and Wiens, two men whose recent smiles once belonged to the realm formerly known as science fiction.