At the height of the euro crisis, Mario Monti, the former Italian prime minister, liked to remark that part of the problem was that “for Germans, economics is still part of moral philosophy”. The suggestion was that the German instinct was to assign blame rather than to fix the problem — and was followed up with a reminder that the German words for guilt and debt are the same.

But the real punchline is that the Germans are right. Economics is — or should be — part of moral philosophy.

Successful politicians have to do more than just deliver economic growth. They also need to offer voters a vision of the economy that makes moral sense — in which virtue is rewarded and vice is punished. Ever since the financial crisis 10 years ago, mainstream politicians in the west have lost that vital ability. The belief that the economic system is unjust has stoked the rise of rightwing and leftwing populism across the west.