Economists have allowed themselves to walk into a trap where we say we can forecast, but no serious economist thinks we can. You don't expect dentists to be able to forecast how many teeth you'll have when you're 80. You expect them to give good advice and fix problems.

There's nothing wrong with a plan, but remember Von Moltke's famous dictum that no plan survives first contact with the enemy. The danger is a plan that seduces us into thinking failure is impossible and adaptation is unnecessary - a kind of ‘Titanic' plan, unsinkable (until it hits the iceberg).

I see the God complex around me all the time in my fellow economists. I see it in our business leaders. I see it in the politicians we vote for - people who, in the face of an incredibly complicated world, are nevertheless absolutely convinced that they understand the way that the world works.

Accepting trial and error means accepting error. It means taking problems in our stride when a decision doesn't work out, whether through luck or misjudgment. And that is not something human brains seem to be able to do without a struggle.

There is much more to life than what gets measured in accounts. Even economists know that.

You show me a successful complex system, and I will show you a system that has evolved through trial and error.

Pluralism matters because life is not worth living without new experiences - new people, new places, new challenges. But discipline matters too; we cannot simply treat life as a psychedelic trip through a series of novel sensations.