No—Homeopathy does not work
For the future, I plan to not be drawn into discussions of whether homeopathy works or various aspects of the argumentation and evidence in the issue—be it with Robert Hahn or someone else. (Separate posts on specific sub-issues may still occur, however.) Instead, I will simply link here—with the request that the supporter of homeopathy read the below links and refute the discussions present there first. In the exceedingly unlikely event that he manages to do so, I will be willing to reopen the issue.
The following lines of counter-arguments are faulty and/or dishonest and will not be accepted:
The claim that experimental evidence shows that homeopathy works; in particular, in combination with the claim that attempts to e.g. point to a lack of a known mechanism are merely a cover-up intended to discredit this “fact”.
As pointed out repeatedly in the links, experimental evidence speaks against homeopathy. The accepted (weak) effects are all explained by non-medicinal factors. (Cf. the item on anekdotal evidence.)
Exception: If, theoretically, the supporter can show a subsequent change in scientific consensus on experimental evidence, this is obviously allowed. I stress that merely pointing to the existence of a few hundred published-in-CAM-journals papers are not enough—consider the number of studies showing the opposite, the significantly lower credibility of these journals compared to the leading mainstream journals, the often lower scientific value (worse methodology, smaller samples), and publication bias. Also note the discussions of meta-studies, including Linde’s, in the linked-to articles.
Ad hominem towards the authors or their sources (including accusations of self-interest or being bought by the pharma industry): If their ideas, reasoning, or facts are faulty—attack these instead. If not, well, then there is no justification whatsoever in attacking the man. Also bear in mind that it is the homeopaths who have the greater self-interest in the issue (i.e. any attack based on self-interest will strike even harder in the other direction) and that it is exceedingly unlikely that the totality of the opposition would be faulty in this regard.
Exception: If a convincing case can be made against an individual debater, study, whatnot, with regard to e.g. methodology (not merely an alleged motive) then this may obviously legitimately be used to question an individual statement or result.
As a special case: Denying non-homeopaths the right to speak on the issue. These may be less knowledgeable in the subject field, but may also bring superior knowledge or ability in other areas, including scientific methods or critical thinking. The denial is particularly weak when the outsiders are medical researchers from other areas. Further, good and correct science can be explained to outsiders in a way that is convincing—if some field as-good-as-consistently fails to do so, then this speaks strongly against it. Science bears up to scientific scrutiny and critical investigation by outsiders—quackery does not. Indeed, unwillingness to allow outsiders the opportunity to poke holes and unwillingness to constructively engage critics are themselves strong (but not conclusive) indications of quackery.
Further note that the critics are not limited to outsiders. The possibly most notable examples are Edzard Ernstw and Willem Betz, who were both once homeopaths and now are vocal critics.
Anekdotal evidence: “I know that homeopathy works! I have tried it succesfully myself.”
There are a number of reasons why individual experiences can seem to indicate that something works when it, in fact, does not. Cf. some of the below links.
Among explanations we have e.g. the placebo effect, coincidence and natural healing (if a thousand sick people take a particular preparation, at least some of them are likely to, by themselves, become healthy at the “right” time by sheer coincidence), an increased tendency to take medicine when a problem is at its peak, confirmation bias, and “extra-medicinal” factors like a better patient–physician relation. Further note that it is not inconceivable that some less-than-religious homeopaths would prescribe conventional medicine every now and then…
Primary sources should be used with caution in any attempt at refutation (but are certainly allowed): There is much value in primary sources, but they are also dangerous and, if possible, secondary and (to a lesser degree) tertiary sources are to be preferred (just as with e.g. Wikipedia’s take on sources). Note e.g. the greater risks of partiallity, statistical noise, methodological errors, and mis- or over-interpretation when using primary sources. This is particularly important for laymen, who often draw too fargoing conclusions from research (as proved by any number of journalists over the years). Note also that if a primary source claims X, then there may be two others that claim non-X.
A common counter-argument against clinical studies, that homeopathy would demand an individual treatment and that merely giving every patient the same cure is misleading, does have some merit. However, I am well aware of it, it is not (taken by itself) enough to convince, and there is no need to repeat it. Consider that better results in individual treatment are also what a non-medicinal explanation predicts (in particular, when several remedies are tried until something “works”), that clinical trials are still valid investigative tools (if a particular remedy is good for only one in ten, then this should still make a noticeable difference in a large enough sample or a meta-analysis), and that the alleged extreme inconsistency in results is contrary to what would be expected a priori if a medicinal effect was present (the mechanims in the human body are very similar from person to person and so complete deviations in result are very rare, allergies and over-sensitivities excepted). Further, the obvious main line of homeopathic research would then be to find better classifications and groupings to systematically pin-point the right remedies, with uses including better treatment, integration of similar methods into school medicine, and … building better samples for clinical trials. Such attempts have not been successful, which speaks strongly for a non-medicinal explanation of any success stories. Indeed, by Occam’s Razor, it is more likely that the different effects on individuals are either just an excuse or a misinterpretation of events—not an actual difference.
On with the links:
http://en.wikipedia.org/wiki/Homeopathye Note the extensive discussions pro and contra on the talk pages.
http://www.sciencebasedmedicine.org/?p=11e Note: First of five parts. The other parts are linked from there.
http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/45/45.pdfe A thorough parliamentary report (UK) which includes both a high level conclusion and (in the appendix) more detailed statements and research overviews. A brief non-PDF summary from a different sourcee.
http://apgaylard.wordpress.com/2009/09/06/a-homeopathic-refutation-part-one/e (The second part deals with the dangers of homeopathy and is of little relevance to this particular discussion.)
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1874503/table/tbl1/e Overview of meta-analyses and re-analyses based on a much-touted-by-homeopaths work by Linde. (Similar, more extensive tables are present in the PDF report above.)
Also of interest:
http://www.quackwatch.com/01QuackeryRelatedTopics/holmes.htmle A long, very well-argued, and well-known refutation of homeopathy by Oliver Wendell Holmes; however, also a very old text, which could be unfair to the homeopathy of today in at least some regards. On the plus-side, it shines some light on why there really was no reason to expect homeopathy to work in the first place.
http://www.ukskeptics.com/article.php?dir=articles&article=it_works_in_animals.phpe A brief view on homeopathy and animals—a topic otherwise given little space in the linked-to articles.
http://www.sciencebasedmedicine.org/?p=4e A broader discussion of alternative medicines and pitfalls. Generally, this site (also present with an article series above) appears to have a large number of articles of direct or indirect relevance.