The current fascination with self-help and New Age philosophies, along with the popular theory that the mind and body are interactive, have encouraged a sense of personal responsibility for illness. According to Dr Weil, it is when this emphasis on personal responsibility is taken to an extreme that a damaging sense of failure and guilt results, inhibiting recovery.
Considering his impeccable credentials in alternative healthcare, Dr Weil's approach may surprise delegates at a conference exploring positive states of mind, "The Question of Hope", to be held by the Bristol Cancer Help Centre at Bristol University on 7 October.
A Harvard-trained physician, he practises natural and preventive medicine in Tucson, Arizona, where he is setting up a training programme in "integrative medicine", combining conventional and non-conventional approaches.
Cancer, he believes, is more likely to result from a complex interaction of genetic and environmental factors than from negative feelings. "I reject the idea that people give themselves cancer by failing to express anger and other emotions. And I emphatically reject the notion that failure to heal presents any kind of judgement about a person's state of mind or spirituality." He's not the first to express such concerns, but he goes farther than most. "Affirmations", a widely accepted technique to boost positive attitudes, arouses his suspicion. Repeating such phrases as "I am filled with healing energy" and "my gallstone is getting smaller and smaller" is thought to enhance the healing process. Dr Weil is not so sure. "In my experience it's not very effective. On the other hand, if you can put a patient in touch with someone else who has been healed of the same condition, that's a powerful way of overriding the negative programme they may be in."
He doubts that support groups, also fashionable, can achieve this either. "I see these groups do a lot of damage, because they throw people with others who are much sicker and who reinforce the idea you're going to have this for ever. People even learn new symptoms in ME support groups."
Unexpected emotions can influence the progress of disease, he says, and a fighting spirit is not always the best approach. Sometimes "letting go" can be more effective, when people accept everything about themselves, including their illness. On the other hand, intense feelings such as falling in love - or even anger - can prompt dramatic healing responses. "New Age therapists who teach people to rid themselves of negative emotions may not like to hear this," says Dr Weil, "but facts are facts." One man, suffering from an auto-immune disease that destroyed his blood cells, felt a surge of rage as he lay sleepless in hospital one night. Within hours his red-cell count began to climb. He was discharged within days.
At every level of the body, from DNA up, mechanisms of self-diagnosis and regeneration exist, ready to become active, he says. But how can we trigger them? Why should one method work for one person and not for another? He admits that no one knows. "We may not know in any individual case how to do it, but to operate from the premise that it's possible is very important."
Spontaneous healing, or remission, arouses mixed feelings among conventional physicians. According to Professor Michael Whitehouse, director of the Cancer Research Campaign, Wessex Medical Oncology Unit, such phenomena are part of the spectrum of cancer. "Obviously, there are idiosyncratic behaviours, but it's a characteristic of the cancer, not the host."
Even Dr Weil concedes that cancer is a special case, and genuine remissions rare. Beneficial results are more likely with chronic and stress-related conditions such as irritable bowel syndrome, allergies, eczema and auto- immune disease such as rheumatoid arthritis.
Meanwhile, Dr Allan House, senior lecturer in liaison psychiatry at Leeds General Infirmary, probably speaks for many doctors: "It's an intriguing idea that one's state of mind can affect conditions with an immune basis, such as HIV and cancer in remission, but evidence that this has an impact on disease outcome is not there yet."