On the coffee theory of disease.

Samuel Hahnemann was born in Meissen, in Saxony, in 1755. He studied medicine in Leipzig, Vienna and Erlangen. After graduation in 1779 he returned to Saxony and became a family doctor in Mansfeld. He got disappointed by the way he was expected to practise medicine and became very much opposed to widespread practices such as bloodletting. In his eyes, what he had to offer his patients did sometimes more harm than good. Not only did it not cure them from their diseases, they fared worse because of the noxious effects of the medicines he prescribed them. He apparently was an early adopter of the 'Too Much Medicine' notion (Moynihan and Smith, 2002; Macdonald and Loder, 2015). Disillusioned he left medical practice after only a few years and embarked on a more contemplative career. In his 1803 publication 'On the effects of coffee' he developed the theory that substances that come close to medicines, such as snuffing, smoking or eating opium, consuming chocolate and drinking coffee are bad: 'Coffee is a purely medicinal substance (.. .), no healthy person ever drank unsugared black coffee for the first time in his life with gusto' (From: The lesser writings of Samuel Hahnemann, 1803, pp 391 –408; www.books.google.com). He soon abandoned the coffee theory in favour of the 'psora' theory (chronic diseases are caused by accumulation of waste products in the body). He was a man of theories, a true champion of Romantic medicine. His claim to fame however came with his introduction of homeopathy, a theory pretending that substances that cause disease in healthy persons may heal the same disease, if diluted infinitesimally (not a single molecule left), and only after vigorous smacking it into a leather bag between dilutions. One would expect that improbable theories like this, lacking biological plausibility and scientific credibility, would have been debunked immediately. As was the coffee theory, as was the psora theory. Not so homeopathy however. Even today, in 2015, PubMed returns over 5000 hits, many of them to recent publications. And these papers typically conclude that '.. . the currently available evidence is neither conclusive nor comprehensive enough to provide a clear picture of the use of homeopathy in patients with disease xxxx', or: 'There are large gaps in the body of evidence concerning the role of homeopathy in the treatment of illness yyyy'. And. .. off goes the next generation of passionate researchers in …