There is nothing more likely to raise the hackles of any self-respecting rationalist than to be confronted with the latest celebrity story about the miraculous healing power of homeopathy or some other ‘alternative’ or ‘complementary’ quackery. Or, embarrassingly, to discover that some of your best friends are also devotees.
This isn’t a new bugbear in response to some kind of New Age, middle-class hippiedom. Charles Darwin wrote in a letter to a cousin:
You speak about Homeopathy; which is a subject which makes me more wrath, even than does Clair-voyance: clairvoyance so transcends belief, that one’s ordinary faculties are put out of question, but in Homeopathy common sense and common observation come into play, & both these must go to the Dogs, if the infinitesimal doses have any effect whatever.
There is no serious scientific debate about the efficacy of homeopathy. It performs no better than placebo and is