We are all free market economists now. They think we are more likely to be motivated psychologically by greed than anything else- indeed, they say it is the only consistent human motivation. Sadly, that may well be true. And that is the justification for regulating markets, for imposing, in the interests of a wider collective interest and benefit, limits on how far greed is allowed to motivate us, and how far its clutches can go.

If greed is good for the economy - and right now it appears that it has done us harm rather than good, with soaring oil prices and too many people playing markets in such a way that others are harmed, as in the sub-prime market, and in house repossessions- it may be bad for human beings. Greed makes us all consumers, all searching for the next thing, the next experience, the next possession. But, as Richard Layard and others have pointed out so forcefully, this consumerism, this restless seeking after yet more possessions, does not make us happy. Richer we maybe, but happier we are not.

So the conclusion has to be that greed may well fire economies, but old wisdom, in all our faiths, about giving 10 percent of what we have away, about social justice evening up between the haves and the have-nots, has real relevance today. It cannot be right that disparities between rich and poor are growing. If that's the effect of greed, whatever is does for the economy, it is appalling in its impact on humanity- and we should temper its effects still more, and realize that it may be the consistent motivation, but that does not make it right.