Compared with what ordinary people are going through in Afghanistan right now, and the reasons for worrying for the future that they have, we haven't that much to worry about.

You can poison your life by worrying too much. Whoever did the Two Towers is, in the overall scale of things, small and weak. No batteries of hundreds of H-bombs in supersonic rockets, or atomic submarines prowling around the globe.

Keep it in proportion. It was a horrible thing and a dreadful shock and unexpected. But the scale of it didn't compare with that of many earthquakes. Grieving is right, and thinking about priorities is right, but not panic.

One of the most sensible ways to respond to all this would be for people to realise that it's more important to spend time with the people they love rather than working all God's hours to get more money than they need. And to cut down on those needs. All right the economists might not like that kind of response, but that just means people need to reshape an economy that encourages us to waste our lives.