By trying to highlight the most important issues at crucial moments in the global conversation, these debates not only profile the ideas and solutions of some of our brightest thinkers and doers, but crystallize public passion and knowledge, helping to tackle some global challenges confronting humankind.

— Peter Munk

I think many of the worst movements in history have been born out of the minds of people who believed in perfectionism — scientists, politicians, and others who thought that we could straighten things out, once and for all. And this is an incredibly dangerous philosophy of life. The perfectionists amongst us are those who very often ruin and wreck the world. And true human progress is often the work of people who are much more modest, who accept their own flaws and the flaws of others, and are not attempting to make a paradise on earth.

We think this world is a “vale of tears,” a “slough of despond” compared with what it could be — and will be in the future — if we do the right things. I’m not an optimist by temperament, but by evidence. That’s what changes my mind. We’re not saying, “Don’t worry, be happy.” We’re saying, “Don’t despair, be ambitious.”

Progress has been real, progress is real, progress has been good for the great majority of people. Progress has been particularly good for poor people. And there’s no reason to think that it’s suddenly going to stop now just because we’re not thinking enough about our soul or our psyche.

And the story that always stays with me and I think bears repeating this evening is the story of what’s known as the Petrov incident.

Recently, the epidemiologist Hans Rosling gave a thousand people a series of multiple-choice questions on population, literacy, life expectancy, and poverty. He noted, “If for each question I wrote the alternatives on bananas and asked chimpanzees in the zoo to pick the right answers, they would have done better than the respondents.” The reason was that the respondents consistently picked answers that were too pessimistic.

The cure for cognitive fallacies is data, and the trend lines are unequivocal. On average, people are living longer, healthier, richer, safer, freer, more literate, and more peaceful lives. While past performance is no guarantee of future returns, the world is not Wall Street. We are unlikely to wake up one morning and face a world with smallpox, slave auctions, or surgery without anaesthetics.

Optimism is a self-fulfilling prophecy, so is pessimism. The progress we enjoy is not the result of some mysterious historical dialectic or law of inevitable progress or arc bending toward justice. It is the result of people spotting problems, including fragility and nuclear proliferation, and instead of moaning that we’re all doomed, applying their ingenuity and their efforts to solving them.

As Thomas Babington Maccaulay said a long time ago, in 1830: On what principle is it that with nothing but improvement behind us we are to expect nothing but deterioration before us?