Once upon a time - hundreds of millions of years ago - all the animals were single-celled. each pursued its own self-interest - surviving, eating and reproducing basically. But evolution took a hand and some of these animals found advantages in co-operation In time they changed into fishes, amphibia, dinosaurs - and more recently us.
Our cells are co-operative. They reproduce enough to make our organs and then they stop. Well, mostly. Some selfish cells don't stop but reproduce without limit. To do this they grab from our blood nutrients and oxygen that ought to go to other organs.
We call this cancer. Sometimes it kills us.
Human society is not a super-organism; we do not abandon our own interests and judgement to be part of it. But there are parallels. Both provide benefits, such as safety and access to resources, that the individual units could not get separately, Both require solidarity and self-restraint from those units.
And there are social equivalents of cancer. Sometimes the people in one part of society - a clan, a class or a sector - cease to show solidarity and self-restraint. They grab resources that should go to others and swell up so that they threaten the health, even survival, of the whole.
Today the finance sector is just such a social cancer. It's excesses have brought recession to the whole developed world and fierce austerity to Iceland and Ireland - and probably to Greece and Italy in the near future. It has grabbed a great share of our resources and, by increasing inequality, made our societies worse places to live. And it's compulsive pursuit of profit and growth is a major driver for the greenhouse gas emissions which are likely to make the planet deeply hostile to the societies of which it is part.
The finance sector is, like a cancer, damaging social health and threatening social survival. It must be cut back to size and made to see that it must be a partner not a ruler.
Though this blog is about climate change I believe that we cannot solve those problems without putting finance back in its proper place.