The absolutist takes himself to read nature in her very own language, but the relativist insists that nature does not speak, and we hear only what we have elected to hear.

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.

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.

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 lays down the law, but the relativist hears only roaring and bawling. Or, when the relativist voice, as it is heard from philosophers such as Nietzsche or James, itself starts to grate and sounds shrill, as it often does, and when the relativist then offers concessions, the absolutist hears only insincerity. The war of words can often turn into a dialogue of the deaf, and this too if part of its power to arouse outrage and fury.

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.