The other day I heard a wildly optimistic account of how our understanding of genetics would allow us to eradicate many diseases, potentially create better people, and reduce health costs. I’m sceptical about all of these claims, but I was taken back to a strange meeting I attended in Germany perhaps 20 years ago.

David Weatherall, Britain’s “top doc,” invited me to attend a meeting in a schloss in Germany that had belonged to one of Queen Victoria’s many nephews. I couldn’t think at the time why he invited me, but older as I am now I guess that he had to come up with somebody at short notice—and I’d just crossed his horizon at a meeting on genetics.

It was at a time when we introduced a policy at the BMJ of not being paid by anybody else to attend a meeting. I learned that we would be entertained by a string quartet, and I wondered if I ought to pay for the second violin.

The schloss was grand and the food excellent. There weren’t many people at the meeting, and I sat at a round table literally between two Nobel prize winners, a young one who had discovered monoclonal antibodies and an older one who won his prize for something genetic shortly after Crick and Watson.

Now I remember a time when I felt intimidated by somebody who was clever enough to pass the 11 plus, an exam you had to take in my day to qualify to go to a grammar school. Once I had passed mine I moved up to being intimidated by somebody who had seven O levels. And so it went on up the scale to getting a degree. But I discovered that as I passed these things myself you didn’t have to be that smart. Now I achieved the ultimate and learnt that Nobel prize winners could be pretty dumb. The monoclonal antibodies winner, presumably a convergent thinker, had nothing useful to contribute, while the older prize winner couldn’t stop himself talking to the point where most people there wanted him to shut up.

The reason I remember the meeting so well is because of a talk by Jonathan Glover, the then Oxford philosopher, who had written a book called “What Sort of People Should There Be?” I’d read the book and admired it. It started with the idea that ethicists were often struggling to keep up with science, and Glover had a way for ethicists to get ahead—by conducting a thought experiment.

In his book and his talk in Germany he proposed that anything was possible: people could be made taller, smarter, happier, more beautiful, anything. That day might come scientifically, and it would be useful to prepare for it. His talk was witty and his tone light. I remember him homing in on aggression. What if we could design out of people the tendency to go to war? Millions of lives could be saved, and we could avoid lands laid waste.

Most of his audience were German, and imagine how Germans might have felt. Here was an Englishman cracking jokes about creating certain sorts of people and doing away with other sorts. Was he not aware of Germany’s painful past of eugenics and destroying undesirables?

Presumably Glover was aware, but perhaps he’d forgotten. Or maybe he’d miscalculated. Anyway the result was that the audience grew frostier and frostier, and Glover began to realise his mistake. It was uncomfortable being there.

The moral of this tale is not simply to not joke about eugenics, but more to think not just about your talk but also about your audience. I made a similar mistake, giving a talk to surgeons in Australia entitled “Is Surgery an Anachronism in an Evidence-Based Age?” My answer was yes, which for the audience was the wrong answer.

Competing interest: RS had his expenses to attend the German meeting paid by the BMJ, but it didn’t pay for the second violin.

Richard Smith was the editor of the BMJ until 2004 and is now chair of the board of trustees of icddr,b [formerly International Centre for Diarrhoeal Disease Research, Bangladesh] and chair of the board of Patients Know Best.