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.

The absolutist takes himself to speak to the ages, with the tongue of angels, but the relativist hears only one version among others, the subjectivity of the here and now.

There may be rhetoric about the socially constructed nature of Western science, but wherever it matters, there is no alternative. There are no specifically Hindu or Taoist designs for mobile phones, faxes or televisions. There are no satellites based on feminist alternatives to quantum theory. Even that great public sceptic about the value of science, Prince Charles, never flies a helicopter burning homeopathically diluted petrol, that is, water with only a memory of benzine molecules, maintained by a schedule derived from reading tea leaves, and navigated by a crystal ball.

The absolutist parades his good solid grounding in observation, reason, objectivity, truth and fact; the relativist sees only fetishes.

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.

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.

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.