Want to make a fool of yourself? Commit a logical fallacy. Want to make a bigger fool of yourself? Incorrectly employ a logical fallacy. Indeed, if there is anything more detested on the internet than the incorrect answer to a question (see Cunningham’s Law), it’s incorrectly qualifying a statement as fallacious. While there is a term for grammar mistakes that are made in the correction of grammar, no such equivalent exists for fallacies generally (as far as I can tell).

Some time ago, I wrote an article criticizing a chiropractor for not understanding basic science and using a diagnostic technique that would constitute health fraud if he wasn’t just ignorant. In essence, the tool (an ear thermometer) has legitimate uses, but it was used in an invalid capacity to infer the existence of a biological construct that is – as far as modern science can tell – purely mythical. This is the chiropractic subluxation.

In my first draft, I had the gall to compare the practice to ghost hunting. For reference, ghost hunters employ a range of legitimate measurement tools in the pursuit and quantification of the paranormal. Just like with the chiropractor, they use legitimate tools inappropriately to infer the existence of something that probably doesn’t exist. Just like the chiropractor, they evidently believe that their tools infer the existence of unproven entities. Quite apropos, non?

I ended up removing the ghost analogy in an early draft (I largely felt that it was unnecessary filler, as I often do with my attempts at comedy). Nonetheless, was it a fair comparison? Not according to your friendly twitter chiropractor (a different chiropractor than from the article):

Because the response was to my article, I first thought this must mean that the friendly twitter chiropractor was served some form of internet cache of an old version of my draft. I surmised that his internet provider must provide a robust caching service to save all that sweet bandwidth that would otherwise be lost to logical fallacy cheat-sheet queries. As with Cunningham’s law, it’s worth remembering the old adage: the internet never forgets.

Then again – in this case – the internet did forget and it turned out that I’m just not that original; another contributor made the same connection I first did:

Did we commit a logical fallacy in this analogy? Let’s unpack.

A reductio ad absurdum is actually not a fallacy. In fact, it’s a valid and essential logical tool for either proving or disproving a statement based on the inevitable conclusions that must be made by following the statement to logical extremes. If I say – for example – that the more I roll a ball of snow, the bigger it will get, one can dismiss the truth of the statement on the grounds that a ball of snow cannot get bigger than all of the snow on the planet. This extreme example proves that at some point, I will no longer be able to make the ball bigger with more rolling.

While a reductio ad absurdum is not a fallacy itself, the argument can be used fallaciously. If – for example – I claimed in my article that the scientifically-confused chiropractor must believe that only an ear thermometer is required to diagnose any disease because he used it in this one case, that would be a fallacious argument. It is not, however, a reductio ad absurdum fallacy – such a thing does not exist. Rather, this would be a straw man fallacy, which involves the misrepresentation of the initial premise. Indeed, incorrect use of reductio ad absurdum arguments often result in straw man or slippery slope fallacies. Instead, when illustrating why spinal thermography with an ear thermometer is an invalid practice, comparison to ghost hunting is employed as a comedic device to illustrate the palpable silliness of grown adults hunting for things that likely do not exist.

This would be an opportune time for a deprecating remark about the quality of chiropractic education, but I would hate to provoke twitter warriors with logical fallacy keyboard macros to wrongfully conflate my assertion with an ad hominem. Then again, I love a good rant.

Stay logical.