Nature is not simply a technical or economical resource, and human beings are not mere numbers. To suggest that one can somehow align all the squabbling institutions of science, environmental management, government and diplomacy in an alliance of convenience to regulate the global climate seems to me optimistic.

The truth is, of course, that history is not completed in modern commerce any more than philosophy is perfected in political economy. In other words, there is nothing timeless or God-given about filling stations and penicillin and plastic bags.

The year 2008 was a reminder to those who had forgotten that there is such a thing as history and that the cycle of famine and feast in commerce, first identified in antiquity and well understood in the Middle Ages, was not suddenly abolished in modern times.

If good history is dispassionate history, it must naturally wait until the passions of the period subside.

One of the consequences of the Iranian revolution has been an explosion of history. A country once known only from British consular reports and intrepid travelogues is now awash with historical documents, letters, diaries, grainy video, weblogs and secret police files of questionable authenticity.

Bulls don't read. Bears read financial history. As markets fall to bits, the bears dust off the Dutch tulip mania of 1637, the Banque Royale of 1719-20, the railway speculation of the 1840s, the great crash of 1929.

Cause and effect, the riddle of all history, is a particular devil in financial history and never more so than today, where entire classes of security are collapsing not on public exchanges and stock-tickers but because there are no markets to establish prices this side of nothing.

For all their current prestige, Osama bin Laden and the suicide bombers are still regarded in all but the most desperate districts of Gaza or Peshawar as romantics with little chance of more than symbolic victories, however bloody and brutal. That gives both the Middle East and the West a small and distant hope of security.

In rising financial markets, the world is forever new. The bull or optimist has no eyes for past or present, but only for the future, where streams of revenue play in his imagination.

Because bankers measure their self-worth in money, and pay themselves a lot of it, they think they're fine fellows and don't need to explain themselves.