The same man was the model for Jesus Christ and Judas

At Boxmoor County Primary School we had only two pieces of music: Morning by Grieg and Vaughan Williams' Tallis Fantasia. And, as far as I recall, the headmaster, Mr Standen, had only two stories.

One involved two frogs who fell into a pail of cream. One swam around for a bit, but then gave up the struggle and drowned. The second frog swam and swan until his strength was almost exhausted. Just when he thought he could swim no more, he found that the cream had turned to butter and he climbed out.

That is the kind of story that headmasters always tell. It is only when you are much older - and it is far too late to do anything about it - that their truth comes home to you.

His other story was more interesting and I recently came across another telling of it. It is in Gentle Regrets by the Conservative philosopher Roger Scruton. He attributes this version to Monsignor Alfred Gilbey, who was the Catholic chaplain at Cambridge during his own undergraduate days.

It runs as follows:

He also told with great feeling an apocryphal story concerning the composition of Leonardo's Last Supper, which, in this version of event, the artist composed over many decades, constantly searching the streets and alleyways of Milan for the ideal types upon whom to model the twelve apostles, and having begun with the beautiful and innocent face of a young man whose expression seemed to capture all the grace, dignity and tender compassion of Jesus.

After years of labour the apostles had all been assembled, representing in their carefully differentiated expressions the fine gradations of hope, resolution, weakness and despair.

Only one remained and that was Judas, whose baseness no citizen of Milan seemed to wear on his face, and to whom Leonardo began to despair of giving the absolute lifelikeness that was vital to his conception.

At last, in a mean alleyway, a dark figure, engaged in some whispered transaction, caught the painter's eye. Recognising in those fear-filled, treacherous glances the lineaments of Judas, Leonardo enticed him to the cenaculo with a gift of silver.

The figure, shifty, suspicious and huddled into himself, is pushed into a corner and told to sit. Looking up at last, and recognising the painter and the tools of his trade, he says, "You have painted me before."

"Have I?" asks the startled painter. "When?"

"Oh, a long time ago."

"And for what purpose?"

Judas turns to the nearly completed fresco that is taking shape above them.

"There I am, he says, and points to Christ.

In my headmaster's version it was the model for the infant Christ in a Nativity scene who grew up to become Judas, but the idea was the same.

Quite a Liberal story, don't you think?