(scroll down for his section of the article)
The second point - and here is where I am on the side of the Catholics denouncing it - is the film's overt message.
Not once, but over and over again, the professor, played by Sir Ian McKellen and the 'symbologist' Tom Hanks offer the Last Living Descendant of Jesus and Mary Magdalene the chance to blow the whistle on the lie the Church has purportedly been hiding for 2,000 years.
By exposing the marriage of Jesus to Mary Magdalene, Ms Tautou is given the chance to end "all the oppression of the poor, of the powerless, of women - you can put an end to that".
The factual absurdities could all be dismissed by anyone with the smallest knowledge of history. What is harder to dismiss is the blatant anti-Catholicism, which is as crude as any Paisleyite sermon or No Popery pamphlet of the 19th century.
Roman Catholics, of whom I am not one, are surely entitled to wonder what would have happened to the Empire Cinema Leicester Square, where I saw this film, if the figures in the fantasy had been not Jesus and Mary Magdalene but the Prophet Mohammed and his family.
I think it would have been a case for the fire brigade.
A fair reading of history, first of Europe, then of the rest of the world, would speak of many wrongs done by the Roman Catholic Church, including persecutions and holy wars.
But it is also the Church that kept civilisation and learning alive in Europe. And in our own day, the work of Catholics in the poorest places of the world to relieve suffering and identify with the poor puts some other groups, including the vast bulk of stay-at-home secularists, to shame.
There are no good Catholics in this film. The monk-murderer is the militant representative of an Catholic organisation that is portrayed as fraudulent and malignant.
In a free society, we are entitled to portray Catholics as we please, and to debate their faith. As I have already hinted, anti-Catholic prejudice has an old though not very glorious history in this country.
But the reason I found the film depressing was not just that, in its blundering, ignorant way, it was making cheap gibes at Opus Dei, a devout group within the Roman Church.
It was also openly stating that a free and decent way of life was possible only when we had spat upon our past, and kicked away the tradition that for 2,000 years was at the core of all that was most humane and decent in European history - namely the story that God humbled himself to become a poor human being.
Very many of us must have doubted the divinity of Jesus. Yet the respect for humanity shown by Catholics in situations of starvation in Africa or among the shanty towns of South America derives directly from their belief in Jesus Christ as the God-man, who embraced poverty.
To accuse the Church, which has done so much to stand up for human dignity and peace, of being no more than a group of gangsters and perverts is to do much more than just to insult one religious denomination.
It is yet another symptom of our contempt for our past.
Put this side by side with our craven fear of saying Christianity is true and Islamists are in error, and you have more than enough reason not just to boycott The Da Vinci Code - but also to deplore it.