By Melanie Phillips
Encounter Books, £13.99

Many westerners subscribe to one or more of the following propositions, all patently false according to Melanie Phillips. Why they do forms the subject of her far-ranging, absorbing study.

First, in its long-running conflict with the Palestinians, Israel has always been and remains principal aggressor and they principal victims.

Second, the West was taken to war in 2003 on the false pretext that it faced imminent threat from weapons of mass destruction that the Saddam regime had manufactured and was stockpiling.

Third, unless immediate global action is taken to curb consumption of fossil fuels, the planet faces ecological catastrophe from anthropogenic global warming.

Fourth, no question about the universe can be intelligibly raised that science cannot, or will not one day, answer, Darwin's theory of evolution providing a satisfactory explanation of life in its multiplicity of forms.

Phillips's first task is to refute these propositions, on the whole accomplished decisively. Only her refutation of the second point arguably falls short of being entirely convincing. Having established their falsity, to her own satisfaction if not that of all readers, Phillips next sets about explaining how they, and several other and more outlandish beliefs, such as that in the efficacy of witchcraft, acquired currency. Her arresting thesis is that what their widespread currency betokens is the final stage of a protracted, collective breakdown which the Western intellect has undergone since the Enlightenment, when a coterie of French thinkers repudiated all religion.

While much in that 18th-century movement was benign and conducive to reason, freedom and moderation, their dogmatic repudiation of all religion was anything but, argues Phillips.

It contained the seeds of all subsequent utopian totalitarianisms that have since bedevilled humankind.

The first seed to flower did so during the period of Terror following the 1789 French Revolution. More spectacularly gruesome flowerings followed, in the form of Soviet communism and, later, Nazism.

Since post-war revelation of their excesses, Phillips argues, Western reason has lost confidence, thereby opening the flood-gates, via cultural Marxism and cultural relativism, to post-modernism and multiculturalism, the twin, immediate causes of our present-day madness. The first intellectual stance abandons all pretensions to objectivity. The second has disabled the West from mounting any effective defence against the challenges of Islamism.

This has led to widespread acceptance of the Islamist narrative on Israel and US foreign policy, plus other no less false, ideologically driven dogmas championing other supposed victims of oppressive Western hegemony.

At the root of the malady, argues Phillips, lies hostility towards religion, above all towards Judaism, a faith, more than all others, rooted in and conducive to reason and to a humane moral outlook.

Her book is an immensely accomplished piece of writing. How the West can be got out of the hole she has described it as being in will, one hopes, form the subject of its sequel.