When passions are running high, logic may be unwelcome. If we are in love, in despair, or in pain, then it is empathy we crave rather than dispassionate analysis. Anyone with experience in human relationships knows and understands this. Feelings respond better to compassion than rational critique.

This will be the ongoing fault line in ‘evidence-based medicine’. The family of a late stage cancer patient will struggle to appreciate evaluations of experimental drugs. They are grasping for hope rather than striving for knowledge.

The UK government found it hard to manage this tension as patients groups sought license to have expensive new life-extending drugs prescribed. The Cancer Drugs Fund masterminded by Prime Minister David Cameron was recently judged a £1.3billion waste of money. Most of the treatments made no appreciable difference to the experience of the patients. Those that did, offered an average additional 3 months of life. The fund overrode the evidence-based judgments of the National Institute for Health and Care Excellence in order to meet the deeply felt trauma of families facing the death of their loved ones.

Someone, somewhere has to make judgments about health expenditure, but these decisions will not sit easily with those facing pain and death.

Complementary treatments fill a gap here. They are relatively inexpensive and do not need to prove their efficacy. They need not work in order to satisfy people. Scientists will roll their eyes in despair at this, and thus reveal the other fault line in evidence-based medicine. The unity that is body and brain is far more mysterious and complex than we like to admit. We have only a hazy understanding of our neural and biochemical processes. Evidence is partial, not absolute. It is often contested; as should be expected in the practice of science. Amidst a general population looking for hard facts and clear answers, evidence-based medicine is still not quite certain enough. Ineffective ‘natural’ remedies abound.

Evidence-based medicine seeks to more effectively treat our ills. We should welcome those who bring that evidence to bear, especially given how temperamentally and intellectually ill-suited we are to its application.