We are now approaching the critical time of the year for shops and supermarkets: the month before Christmas is the four weeks when stores of all kinds sell their products fastest. Father Christmas means one thing to children: presents. He has no connection with the original St Nicholas, who performed a miracle in providing dowries for three poor sisters, thereby enabling them to marry and escape a life of prostitution.
Human beings are religious animals. It is psychologically very hard to go through life without the justification, and the hope, provided by religion. You can see this in the positivist scientists of the 19th century.
They insisted that they were describing the universe in rigorously materialistic terms - yet at night they attended seances and tried to summon up the spirits of the dead. Even today, I frequently meet scientists who, outside their own narrow discipline, are superstitious - to such an extent that it sometimes seems to me that to be a rigorous unbeliever today, you have to be a philosopher. Or perhaps a priest.
And we need to justify our lives to ourselves and to other people. Money is an instrument. It is not a value - but we need values as well as instruments, ends as well as means. The great problem faced by human beings is finding a way to accept the fact that each of us will die.
Money can do a lot of things - but it cannot help reconcile you to your own death. It can sometimes help you postpone your own death: a man who can spend a million pounds on personal physicians will usually live longer than someone who cannot. But he can't make himself live much longer than the average life-span of affluent people in the developed world.
And if you believe in money alone, then sooner or later, you discover money's great limitation: it is unable to justify the fact that you are a mortal animal. Indeed, the more you try escape that fact, the more you are forced to realise that your possessions can't make sense of your death.
It is the role of religion to provide that justification. Religions are systems of belief that enable human beings to justify their existence and which reconcile us to death. We in Europe have faced a fading of organised religion in recent years. Faith in the Christian churches has been declining.
The ideologies such as communism that promised to supplant religion have failed in spectacular and very public fashion. So we're all still looking for something that will reconcile each of us to the inevitability of our own death.
G K Chesterton is often credited with observing: "When a man ceases to believe in God, he doesn't believe in nothing. He believes in anything." Whoever said it - he was right. We are supposed to live in a sceptical age. In fact, we live in an age of outrageous credulity.
The "death of God", or at least the dying of the Christian God, has been accompanied by the birth of a plethora of new idols. They have multiplied like bacteria on the corpse of the Christian Church -- from strange pagan cults and sects to the silly, sub-Christian superstitions of The Da Vinci Code.
It is amazing how many people take that book literally, and think it is true. Admittedly, Dan Brown, its author, has created a legion of zealous followers who believe that Jesus wasn't crucified: he married Mary Magdalene, became the King of France, and started his own version of the order of Freemasons. Many of the people who now go to the Louvre are there only to look at the Mona Lisa, solely and simply because it is at the centre of Dan Brown's book.
The pianist Arthur Rubinstein was once asked if he believed in God. He said: "No. I don't believe in God. I believe in something greater." Our culture suffers from the same inflationary tendency. The existing religions just aren't big enough: we demand something more from God than the existing depictions in the Christian faith can provide. So we revert to the occult. The so-called occult sciences do not ever reveal any genuine secret: they only promise that there is something secret that explains and justifies everything. The great advantage of this is that it allows each person to fill up the empty secret "container" with his or her own fears and hopes.
As a child of the Enlightenment, and a believer in the Enlightenment values of truth, open inquiry, and freedom, I am depressed by that tendency. This is not just because of the association between the occult and fascism and Nazism - although that association was very strong. Himmler and many of Hitler's henchmen were devotees of the most infantile occult fantasies.
The same was true of some of the fascist gurus in Italy - Julius Evola is one example - who continue to fascinate the neo-fascists in my country. And today, if you browse the shelves of any bookshop specialising in the occult, you will find not only the usual tomes on the Templars, Rosicrucians, pseudo-Kabbalists, and of course The Da Vinci Code, but also anti-semitic tracts such as the Protocols of the Elders of Zion.
I was raised as a Catholic, and although I have abandoned the Church, this December, as usual, I will be putting together a Christmas crib for my grandson. We'll construct it together - as my father did with me when I was a boy. I have profound respect for the Christian traditions - which, as rituals for coping with death, still make more sense than their purely commercial alternatives.
I think I agree with Joyce's lapsed Catholic hero in A Portrait of the Artist as a Young Man: "What kind of liberation would that be to forsake an absurdity which is logical and coherent and to embrace one which is illogical and incoherent?" The religious celebration of Christmas is at least a clear and coherent absurdity. The commercial celebration is not even that.
Umbert Eco, 'God isn't big enough for some people', Sunday Telegraph, 27 November 2005