The scientific world is to be less threatening than was feared. It is to made safe for human beings. And the way to make it safe is to reflect on the foundation of knowledge.

The gods we make in our own image are tribal gods. They tell you how very, very little you should tolerate outsiders, who are less favoured of the Lord. Amazingly, there are no recorded cases of the holy man going up the mountain and finding that it's the others who are right. It always turns out that God wants unbelievers to suffer, and what could be more noble than to help him a little? When religion rules, toleration disappears, for you cannot cherish the verdict of death to the infidels, yet also tolerate those who disagree - for those are the very same infidels.

Wittgenstein imagined that the philosopher was like a therapist whose task was to put problems finally to rest, and to cure us ofbeing bewitched by them. So we are told to stop, to shut off lines of inquiry, not to find things puzzling nor to seek explanations. This is intellectual suicide.

In Michigan recently a man won a lawsuit for substantial damages because, he claimed, a rear-end collision in his car had made him a homosexual.

There are normal times when it is wholly admirable to be steadfast, resolute, unconflicted, and therefore when integrity is unmistakenly a virtue. The person of integrity knows what to do, and does it. But as we have been exploring, there are also times when certainty and single-mindedness indicate something less admirable: a deafness to voices that should be heard or a blindness to aspects of a situation that need to be considered.

This doctrine, that of the ghost in the machine, strictly separates the mind or soul from the body. And by doing so it takes the soul outside the sphere of mechanical or scientific explanation. It splits the world of the mind from the world of science. It is often supposed to protect our cherished free will.

People who have cut their teeth on philosophical problems of rationality, knowledge, perception, free will and other minds are well placed to think better about problems of evidence, decision making, responsibility and ethics that life throws up.