We generally write best of what we ourselves have seen.

There are signs that the age of petroleum has passed its zenith. Adjusted for inflation, a barrel of crude oil now sells for three times its long-run average. The large western oil companies, which cartellised the industry for much of the 20th century, are now selling more oil than they find, and are thus in the throes of liquidation.

Ever since the destruction of Baghdad by the Mongols in 1258, the Muslim world has been in slow decline relative to the west. With Napoleon's invasion of Egypt and the creeping British annexation of Muslim India, that decline took on a malign aspect.

Osama bin Laden, the Saudi-born revolutionary who is believed by most Arab and Iranian observers to be the inspiration of the attacks in New York and Washington, is the best known of the Islamic militants to have emerged in the past 20 years and the least difficult to fathom.

When Gordon the Brown, in London in 1997, commissioned a great inquisition or survey of his new realm, the result was the so-called national asset register (NAR), which was immediately dubbed by the boomers of the UK Treasury "the modern Domesday Book".

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.