Every society clings to a myth by which it lives. Ours is the myth of economic growth...

[We are] persuaded to spend money we don't have on things we don't need to create impressions that won't last on people we don't care about.

Today we find ourselves faced with the imminent end of the era of cheap oil, the prospect (beyond the recent bubble) of steadily rising commodity prices, the degradation of forests, lakes and soils, conflicts over land use, water quality, fishing rights and the momentous challenge of stabilising concentrations of carbon in the global atmosphere.

Questioning growth is deemed to be the act of lunatics, idealists and revolutionaries. But question it we must.

For at the end of the day, prosperity goes beyond material pleasures.

Prosperity consists in our ability to flourish as human beings - within the ecological limits of a finite planet. The challenge for our society is to create the conditions under which this is possible. It is the most urgent task of our times.

Productivity-the amount of output delivered per hour of work in the economy-is often viewed as the engine of progress in modern capitalist economies. Output is everything. Time is money. The quest for increased productivity occupies reams of academic literature and haunts the waking hours of C.E.O.s and finance ministers.