Placebo Argument

Guest Contributor: F. Andy Seidl

Published on February 22, 2010


I was just reading a story in the UK Telegraph, Homoeopathy should not be funded on the NHS, says report by MPs, and thinking, “Well, good; it’s nice to see people acting rationally.”  But then I started reading the comments.

Pure Water It struck me (sadly, not for the first time) how many people simply believe in magic.  In this case, that an infinitesimally small amount of good stuff dissolved in huge quantities of water can have curative powers beyond water alone.  Even if the small amount is so small (e.g., one part in:

1,000,000,000,000,000,000, 000,000,000,000,000,000,000, 000,000,000,000,000,000,000

seriously, that’s a “30C” solution; and you can buy 200C solutions!) that there are actually zero molecules of good stuff, that the water somehow retains a “memory” of the good stuff that makes the potion effective.  You know, magic.

Of the 48 comments on the Telegraph article as I write this, a large number of them were like this one:

“Homeopathy is proven to work as well as a placebo. That contradicts all the critics who say it does not work.”

Seriously.  Do you think he knows what “placebo” means?

n. pl. pla·ce·bos or pla·ce·boes

  1. A substance containing no medication and prescribed or given to reinforce a patient’s expectation to get well.
  2. An inactive substance or preparation used as a control in an experiment or test to determine the effectiveness of a medicinal drug.
  3. Something of no intrinsic remedial value that is used to appease or reassure another.

To restate the obvious (obvious to some, anyway): a placebo is something that works to the extent that it reinforces someone’s expectations but—and this is important—for no other reason.  A placebo is “inactive”, “of no intrinsic remedial value”.

When something is “proven to work as well as a placebo”, that means, basically, that it is proven to not work.  Think about it.  If a treatment produced a better effect than a placebo, we’d all agree that there is something beneficial going on.  In other words, to some degree, the treatment worked.  On the other hand, if a treatment produced a worse effect than a placebo, we’d all agree that there was something detrimental going on.  In other words, it not only didn’t work, it exacerbated the problem.

So, the fact that homeopathy has the efficacy of a placebo means that it was neither beneficial nor detrimental—that it had no effect.  Except, of course, that some people want to believe there is a positive effect and so going through the motions of taking the homeopathic remedy (a.k.a., water) reinforces their expectations of a benefit (and not always for the better.)

Homeopathy critics do not claim that placebo effects are not real and that they can not be beneficial.  They’re only claiming that homeopathy is pseudoscience.  Water has no memory.  There is no magic.

I’m reminded yet again of Tim Minchin’s perfect Storm that poetically captures the ridiculousness of homeopathy claims:

It’s a miracle! Take physics and bin it! Water has memory! And while it’s memory of a long lost drop of onion juice is Infinite, It somehow forgets all the poo it’s had in it!