Religion has been a powerful weapon in the hands of governments, in the hands of priests, in the hands of kings who have used it as a weapon to keep down the populace. It is a wonderful way of disciplining people and making them do what you want, to tell them that if they don't do what you want they will, for example, go to Hell.

Book critics or theatre critics can be derisively negative and gain delighted praise for the trenchant with of their review. But in criticisms of religion even clarity ceases to be a virtue and sounds like aggressive hostility. A politician may attack an opponent scathingly across the floor of the House and earn plaudits for his robust pugnacity. But let a soberly reasoning critic of religion employ what would in other contexts sound merely direct or forthright, and it will be described as a 'rant'.

There is a whole field of inquiry that has come up in the last 30 or 40 years - some call it sociobiology or evolutionary psychology - relating to where we get our moral sense and why we value the idea of altruism, and locating both answers in behavioral adaptations for the preservation of our genes.

DNA is ROM. It can be read millions of times over, but only written to once - when it is first assembled the birth of the cell in which it resides.

Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation forthe existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind's eye. It does not plan for the future. It has no vision, no foresight, no sight at all. If it can be said to play the role of the watchmaker in nature, it is the blind watchmaker.

The machine code of the genes is uncannily computer-like. Apart from differences in jargon, the pages of a molecular biology journal might be interchanged with those of a computer engineering journal.

I personally would go further and say that, if your morality is based, as mine is, on a desire to increase the sum of happiness and reduce suffering, the decision to deliberately give birth to a Down baby, when you have the choice to abort it early in the pregnancy, might actually be immoral from the point of view of the child’s own welfare.