HAMBURG, Germany — The most telling words about a country are often those that are impossible to translate. In the case of Germany, one such word is “Zweckpessimismus.” It means, roughly, pessimism on purpose — the attitude of expecting the worst in order to be able to feel relief when the worst, oh lucky us, does not occur.

People displaying Zweckpessimismus are often annoying. They tend to ruin other people’s fun with their “what can go wrong will go wrong” posture. But Zweckpessimists mostly have a point, like parents warning children against stupid behavior.

This past year, it was the other way around: The Fridays for Future movement, which is stocked and led by young people, is defined by pessimism on purpose toward older generations and their role in driving climate change. Emerging a year ago from the protests of a Swedish teenager, Greta Thunberg, Fridays for Future and its vociferous warnings of an imminent eco-apocalypse has swept across Northern Europe, and is particularly strong in Germany. In June, 500 students linked arms around the Reichstag in an attempt to block legislators from exiting for their summer recess.

It is as easy as it is wrongheaded to ridicule the movement. The young have not only the right to be morally rigorous, but the duty. With age comes intellectual routine, and with intellectual routine comes complacency and operational blindness. It often takes a newcomer’s sense of astonishment to see and break a society’s psychological and social deadlocks — be it the antiwar marches in Washington half a century ago, or the climate strikes in Stockholm and Berlin today.