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.

Life without oil, in fact, would be so different that it is frightening to contemplate. We are addicted, and it is no comfortable addiction.

Viewed from a distance, or through the eye of the All-Knowing CEO of the Universe, the crash of 2008 followed the usual pattern. A long-lived boom driven by cheap credit, going back as far as 1982 (though subject to interruptions in the mid-1980s and 1990s, and in 2001), came to grief because of a rise in the cost of borrowing money.

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.

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.

A century ago, petroleum - what we call oil - was just an obscure commodity; today it is almost as vital to human existence as water.

The world survived the fall of the Roman empire and will no doubt outlast our own so much more splendid civilisation.