This morning, I lent my copy of David Baddiel’s Jews Don’t Count to a colleague. It is a brilliant piece of polemic against the antisemitism of supposedly progressive groups (antisemitism from elsewhere has tended to be a given).

Once, in school, we tried to understand this strangest of prejudices.

‘Mr Poulton, why did people hate the Jews?’

We had been looking at the history of the Bible and the question arose as we thought about the heritage of the Hebrew Scriptures.

The normally noisy class sat attentive.

‘Antisemitism goes back a long time, back to the First Century.  Christians and Jews fell out.  By medieval times Jews were seen by some Christians as the people who killed Jesus’.

‘But they didn’t – the Romans did; they crucified him’, someone called out.

‘You’re right, but the Church said the Jews were responsible.  And there were other reasons.

Christians could not charge interest on money they lent, so people did not want to lend money. So when Venice started to grow in medieval times and businessmen wanted to borrow money, Jews were allowed to come to live in the city to act as bankers.  They lived in part of the city where the iron foundry had been, it was called the word for ‘casting’: ghetto.

Because some Jews were bankers and made money, people resented them.  People began to think that Jews were rich, although there were rich Jews and poor Jews just as there were rich Christians and poor Christians.

So there was the stuff about killing Jesus and the stuff about making money’.

‘But didn’t people dislike them because they thought they were the chosen people?” a girl asked.

‘I’m sure they did. But don’t Christians think the same stuff about themselves?  Don’t we think we are God’s people?’

‘You said Jesus was Jewish; if Jesus was Jewish, why aren’t we Jewish?’

‘Because the Christians wanted to include people who were not Jewish and the traditional Jewish people did not like this and started having prayers in the synagogue that the Christians could not say without cursing themselves; so there was a split about 85 AD and we went different ways.

Maybe a lot of hatred came from the simple fact that the Jews were different; if you lived in times past, the only people different from you were the Jews’.

There was silence.

It was not the best of answers.

How does one explain the deepest of irrational behaviour? David Baddiel’s arguments are far more cogent than mine.