I am writing this on the 25th anniversary of the attack on the World Trade Centre in New York, when terrorists hijacked two planes and flew them into the twin towers of the building, causing them to collapse and kill over 3000 people. That afternoon I had to meet a solicitor; he compared it to the killing of President Kennedy, when a past generation could always remember where they were when they heard the news. He was correct; I was working at Aston University and had just walked into the lab to do an experiment. My colleague always had Radio 1 on; but this time rather than music it sounded like news; then he told me what had happened. We forgot our usual banter and just listened. It is easy to say an event changed the world, but I really think this did; it destroyed the optimism that we were moving to a new era built on liberal democracy and, implicitly, human reason. As it so happens, the attack coincided with the start of the Jewish New Year, a time of inward-looking and self-examination. It is the same idea behind the Christian seasons of Advent and, especially Lent. Sadly, after 9/11, there was very little of this; perhaps as a world we yet again discovered that human reason has it limits in determining human behaviour. Instead, we are left with the insight from the Judaeo-Christian tradition that we are sinners who need to seek a new mind. Today, when we look at the conflicts in the world, we can see what happens when we ignore that.