In 1801, after having performed several trials on the medical treatment Perkins’ tractors and fictitious tractors, the British physician John Haygarth (1740–1827) concluded that ‘Imagination can cause, as well as cure, diseases of the body’. And, he added ‘I have long been aware of the great importance of medical faith. Daily experience has constantly confirmed and increased my opinion of its efficacy’. Haygarth’s statement, which is quoted in Lars Ole Andersen’s book on the history of imagination in medical practice, could hardly have been written as a medical text today. Imagination is no longer a medical term. Nevertheless, the statement is a good illustration of our everlasting fascination with the relationship between body and mind.

Inspired by Reinhardt Koselleck and his theorising on the history of concepts, Andersen starts his book with a discussion on the differences and similarities between different medical concepts. In particular he concentrates on how the concept imagination, which is known as a medical term from the Renaissance, has been used. He discusses how the meaning has changed over time, and how the concept itself has caused social change. The purpose of the book is furthermore to examine the origin of the so-called blind and double-blind trials using intentionally non-effective treatments (placebos) in history. The first trials Andersen pinpoints to 1784, 1799 and 1835.

In the late eighteenth and the nineteenth centuries imagination referred to how body and mind could impose upon each other, and how disease could be influenced by the mind. Besides, it was understood as the messenger that transferred and translated information from the senses into the mind. But, towards the end of the nineteenth century imagination was deprecated in medical discourse, and ‘suggestion’ and ‘psycho-therapy’ took over. The concept ‘was increasingly regarded as a negative force which could cause diseases and weaken the will of the patient’, says Andersen (p. 227). Today, and from the 1950s onwards, we speak about the ‘placebo’, i.e. a treatment which is a simulated medical intervention. And, if the patient has a perceived or an actual improvement in her or his medical condition, we talk about a ‘placebo effect’. However, the notion placebo is much older and stems from the 1780s. In the late eighteenth and early nineteenth centuries, it was defined as medication given to please. The change of concepts and their meaning, says the author, implied a shift from an interest in the faculties of the patient to an interest in the effect of the treatment and the effect of the healthcare provider.

Andersen examines the use and meaning of ‘imagination’ by means of four narratives: the influence of the maternal mind upon the fetus, and three different medical methods, namely mesmerism, Perkins’ tractors and homeopathy, all initiated by physicians in the eighteenth or early nineteenth century. Andersen studies contemporary discussions on the efficacy of the methods, and trials performed to test whether they were humbug or had a real effect. The narratives are fascinating accounts of how physicians have initiated, marketed and practised methods which we today would characterise as suspect and fanciful, if not as pure quackery. However, at the time such treatments were sought by numerous patients all over Europe and in overseas countries, and had plentiful supporters within the medical profession. A hundred years from now, many of today’s medical methods will probably be questioned in the same manner.

Andersen’s account is based mainly on English sources and literature. An obvious question is, therefore, why is the book published in Danish and not in English? Nevertheless, I miss more references to the development of the ideas in Scandinavian countries. Sometimes I find that the author wants too much, and that his many questions are neither clearly posed nor clearly answered, and that there are too many repetitions. Neither do I find his last chapter, where he draws the line from the eighteenth to the twenty-first century, entirely successful. However, the book is an exciting contribution to the history of medical concepts, medical practice and shifting views on the connection between body and mind.