Danah Zohar, Ian Marshall

Nothing is more vulnerable and ephemeral than scientific theories, which are mere tools and not everlasting truths Carl Jung

It is difficult to find a section almost anywhere in this book that is philosophically or intellectually credible. When I read it, I felt I was not engaging with the authors' minds; I continued because I wanted to find out what they are saying, and then I went back and realised why I feel no rapport with them: there are too many unexamined assumptions and questionable attitudes.

At the beginning, the authors suggest that Carl Jung's ideas can be contained and explained within the parameters of neuroscience. They remark that in his day, neuroscience was "insufficiently developed" to account for his ideas, but this discipline can now do so. In many ways this sets the tone for the rest of the book: an attempt to scientifically intellectualise the intelligence which Aldous Huxley called the perennial philosophy. This is such a fundamental misunderstanding that you have to notice it as soon as it appears, and not give the authors credit by reading without discrimination. Otherwise, you become lost in a fictional world of their making.

Zohar and Marshall are professional theorists, trying to present an encompassing intellectual model that conveniently refers to people like Howard Gardner. They suggest that his ideas can be classified into conventional IQ, the 'EQ' of Daniel Goleman and the 'SQ' or spiritual intelligence that they propose. But here is the qualifying remark: they refer to all three of these intelligences and "their associated neural arrangements". In other words the electro-chemical, bio-architecture of the brain is the master science that enables us to map all areas of human and spiritual life.

This assumption is most obtuse; it ignores all philosophical enquiry into the nature of the mind-body relationship and mental-physical causality, and replaces perennial and authoritative models of spiritual understanding with a fashionable brain-reductionism that allows you to feel that you understand what 'spiritual intelligence' is: anything that anyone has ever said or written about it can be located in a brain map.

The authors declare that "spiritual intelligence is the soul's intelligence". They make no attempt to define what they mean by 'soul', what other people have meant by this term, and whether it is valid. Using comparative religion, you could consider the Buddhist view - that there is no such thing as the soul - and examine why they say this. Using philosophical enquiry, you could consider what you yourself know about the soul - if anything - and thereby recognise the difference between spiritual intelligence and belief/idea/religion.

Spiritual intelligence is an investigation into oneself, not external data. The authors do not investigate themselves and their own spiritual reality; rather, they think these answers are intellectual and found in ideas, theories and external and empirical observation, which they refer to at length. They mention that they have a meditation practice, which should be the starting and end point of a treatise like this. Instead, they refer to this fact only in passing, a few times, in a book which is over 300 pages long.

Spiritual intelligence is, by definition, non-cognitive and trans-intellectual. It is not a theory or an idea and important historical texts have made this point paramount. The Tao te Ching begins by saying that the Tao that can be told is not the real Tao; the Zen people use an analogy of a finger pointing to the moon, when you have to remember that the finger is not the moon itself. Zohar and Marshall make the idea equivalent to spiritual fact, and suggest it is all located in and equivalent to the fluctuations of the human brain. They believe that their authority is the same as that of people like the Sufi poet Rumi, that their notion of spiritual intelligence is a meta-model that encompasses religion and spiritual enquiry, and the difference between the two.

The writings of Rumi, like Buddha, Lao Tsu and similar others, are full of spiritual understanding derived from very extensive and very prolonged meditation practice, which precedes cognition. Writings like theirs are based on the premise that you have to find things out for yourself, through meditation.

The authors' misunderstanding is evident throughout the book. A later example is where they claim

It is true of all the spiritual paths that when I walk them with spiritual intelligence I do so in contact with the deepest centre of the self. From that centre 'I am an immovable cause that moves all things' because I and all my actions initiate from the centre of existence itself.

How do they know this? Have they realised it for themselves? Have they walked all the spiritual paths? - this is particularly curious when many religions refer to after death discoveries. Zohar and Marshall link personal experience with abstract ideas, rather than facts they have actually realised. This is mere word-play. Where is this quotation from and how can they legitimately refer to it like this when they have not realised it for themselves? This is the realm of idea and speculation only, presented as authoritative fact. The rhetoric is an odd blend of (questionable) intellectual authority, religion, and New Age romanticism.

Towards the end of their book, the authors refer to Moses "carrying the Law written on tablets of stone". This is Biblical language, which suggests their alignment with the Christian/Judaic outlook. I experienced a kind of double take: these university-influential people insert dubious material like sleight of hand. The Moses remark can be challenged in three ways:

· From the point of view of comparative religion: that all systems are relative, and therefore have questionable authority.

· From a philosophical point of view based on the necessity of personal realisation, rather than received intellectual teaching.

· From a historical perspective where there is extensive evidence that the historical Bible is suspect: we do not really know if Moses existed. And whether he existed or not is irrelevant because it does not change someone's personal position, so this reference is worth nothing.

The authors have developed a scientific model which, they think, encompasses the full spectrum of human and spiritual experience. The text is peppered with occasional insight like a comment that religion is a top-down set of beliefs - but then they refer to those beliefs as if it is advantageous and enlightening to do so. And they note "one of the most profound new insights of twentieth-century science is that wholes can be greater than the sum of their parts". Well yes, but this intuitive fact is not new and it is so obvious that saying science has recently recognised it, and this is an enormous development, is like saying a child who has just discovered that fire hurts is a cognitive breakthrough for us all.

There are additional contradictions. They claim, quite reasonably, that "spiritual intelligence cannot be quantified". Elsewhere in the book, they declare that spiritual discovery is equivalent to what scientists have called 'the God spot' where "the brain's unitive experience emanates from the synchronous 40 Hz oscillations that travel across the whole brain". Brain theory is the master science - and this is based on eminently quantifiable data. The reference to 'experience' is also suspect. There is no reason to think that 'spirituality' is an experience. 'Experience' is, by definition, something impermanent and transitory. Most spiritual writings describe discoveries that transcend normal temporal limits (including birth and death). If they transcend temporal limits they cannot be impermanent moments and are thus more correctly defined as realisations rather than experiences.