The late 1980s was an interesting time for a young biologist to start an academic career as a researcher on homeopathy. Amidst the aggravation in homeopathy bashing due to Benveniste’s Nature paper, Christian Endler received a research grant to investigate two historical models investigating the influence of high potencies – one on amphibians and the other on wheat seedlings. His no-nonsense style plus his perspective as a biologist (rather than a homeopath) soon led to his work gaining recognition within the homeopathic research community and beyond.

As a meticulous experimenter, Endler was aware of possible laboratory pitfalls; he therefore organised multicenter studies which scrutinised (and often confirmed) his findings. Edzard Ernst – a well-known critic of homeopathy – even published the multicenter results on highly diluted thyroxine and frog metamorphosis in one of the journals in which he is an editor.

Keen on travelling (preferably by train!) and fluent in several languages, in 1994 Endler brought together the most important international heads in biological research on homeopathy to publish the seminal book “Ultra High Dilution” – described by Peter Fisher as, “a landmark in the evolution of research in homeopathy”. A professorship and teaching assignments in research methodology followed, with students’ master theses and dissertations on the topic of homeopathic potencies emerging at regular intervals.

In a demonstration of his long-term commitment to the topic of high potencies, in 2015 Endler and colleagues organised “Ultra High Dilution 1994 revisited after 21 years” as a special issue of the journal Homeopathy: the original authors from 1994 (or close laboratory colleagues) contributed papers covering their follow-up research on the experiments and models originally presented in the book.

“Taking a stand for homeopathy seemed both necessary and worthwhile”, Christian told me, and: “I think biology has contributed a lot of really interesting data, so now I will sit back and wait for you guys from physics to deliver the academic breakthrough.” However, true to himself, Christian did not ‘sit back’. He has recently qualified as a psychotherapist (“because metamorphosis goes on”) and is starting a project on low dilutions “to be able to better discuss the principle of similarity with mainstream biologists”, setting out a fresh path for his next ‘over-60’ chapter.

– Dr Alexander Tournier