Yoga, as a system of preventive medicine based on a programme of physical and mental exercises, made it possible to control voluntarily functions which are normally automatic; as part of a spiritual discipline, Hindu or Buddhist, it prepares the way for the extinction of individual self-conciousness. "Fear", said the book, "arises when there is another". So if there is no other person in the world, there can be no fear. Exercises, under the guidance of a guru, taught the disciple that his individuality was an illusion and his soul part of the universal soul. The price of banishing fear, in other words, is to cease to be a person in the normal sense.

Living in towns, illuminated at night and guarded by police, diminished (for a time) the fear of violence, while prosperity and the welfare state reduced the number of those who feared famine, homelessness, illness, unemployment, old age. Nevertheless, the present generation spends far more money insuring itself against these fears than ever its ancestors paid churches or magicians for protection.

Hypochondria diluted fear with hope, and provided an alternative way to Know Thyself. The American woman who got into textbooks for having made 548 visits to 226 physicians and 42 medical students, obtaining 164 different diagnoses, never despaired.

Since the eighteenth century, security has become, almost universally, the official goal for this life, but an unattainable goal, a paradise, ever harder to locate, invisible in a cloud of doubts. The American constitution proclaimed the right to security, which meant the right to have no fears, but in vain. Psychoanalysts declared security to be necessary for the attainment of normality, but few people believe they are entirely normal. Insecurity has become the commonest complaint of our time. Odin the Unpredictable is no longer admired.

The most important discovery of science about fear, however, is that its physical symptoms, in terms of the chemicals produced to defend the body, differ only in degree from those of curiosity. That makes it easier to understand how people racked by fears have been able to escape them or forget them under the influence of curiosity, of a preoccupation with some goal which so absorbs them that they behave as though they were profoundly coureagous.