Compassionate doctors sometimes lie to patients about the severity of their condition, and it is not always wrong to do so.

Explaining is a difficult art. You can explain something so that your reader understands the words; and you can explain something so that the reader feels it in the marrow of his bones. To do the latter, it sometimes isn't enough to lay the evidence before the reader in a dispassionate way. You have to become an advocate and use the tricks of the advocate's trade.

Imagine a crime series in which, every week, there is a white suspect and a black suspect. And every week, lo and behold, the black one turns out to have done it. Unpardonable, of course. And my point is that you could not defend it by saying: "But it's only fiction, only entertainment."

People like to trace their ancestry.

The time has come for people of reason to say: Enough is Enough! Religious faith discourages independent thought, it's divisive and it's dangerous.

They are in you and me; they created us, body and mind; and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.

I doubt that religion can survive deep understanding. The shallows are its natural habitat. Cranks and fundamentalists are too often victimised as scapegoats for religion in general. It is only quite recently that Christianity reinvented itself in non-fundamentalist guise, and Islam has yet to do so.