The Bull Shit Detection Rules…

Every now and then I like to read ‘other’ stuff to get away from physio stuff, and I have recently been reading a book called “The Demon Haunted World”. This was published in 1995 by Carl Sagan and takes a look at the wonders of our universe, science as well looking at how critical, scientific thinking is desperately needed and essential for all that we do and how we all need to improve in it.

For those of you who don’t know who Carl Sagan is he was not only a brilliant scientist, but also a great philosopher, sociologist, psychologist, critical thinker, poet, sage, writer and orator with a fantastic ability to pass on knowledge. His ‘pale blue dot’ being one of his famous works, and is well worth a few minutes of your time to watch right now to put you and your importance in this universe into some serious perspective.

Now in ‘The Demon Haunted World’ Sagan lays out the best ways and methods to help us distinguish between ideas that are valid and scientific, and ideas that are nonsense and pseudo-scientific, for which a lot can found within physiotherapy teaching and practice.

In a chapter called ‘The fine art of baloney detection’ he discusses how we are all susceptible to many types of deception, from tv sales and marketing, to religious beliefs, and of course false scientific claims. He also reminds us that falling for marketing scam, religious dogma, and pseudo-science doesn’t make us stupid or foolish, just naive and ill informed.

However, in an attempt to avoid this happening Sagan advises that we equip ourselves with nine baloney detection rules, or what I’d rather call bull shit detection rules.

And after the many discussions I have had with many clinicians about much pseudo-scientific bullshit in our profession, such as trigger points, dry needling, spinal manipulations, neon coloured stretchy tape, motor control exercises to name a few, I thought I would share Sagan’s Bull Shit Detection Rules and hopefully help you spot it too.

The Bull Shit Detection Rules

No1: Wherever possible there must be INDEPENDENT unbiased confirmation of the “facts.”

That means any research trial published that shows an effect or not needs to be reproduced by another independent party BEFORE we can claim there is or isn’t an effect.

No2: Encourage open honest and substantive debate on the evidence by proponents from ALL sides.

This means open, honest, transparent, public debate and discourse is needed by all interested parties regardless of their position or standing, and not only limited to just those with affiliations or connections in closed and private meetings.

No3: Arguments from an authority carry little weight.

Authorities have made mistakes in the past, and they will do so again in the future. There are NO authorities; at most, there are experts, but this still does not make them immune from questioning or challenging.

No4: If there’s something to be explained, think of ALL the different ways in which it could be explained.

Think of tests you could do that might systematically DISPROVE the alternatives. What survives among the “multiple hypotheses,” has a much better chance of being the right answer than the first idea that caught your fancy.

No5: Do not to get overly ATTACHED to a hypothesis just because it’s yours.

Ask yourself why you like the idea. Compare it fairly with ALL the alternatives. See if you can find reasons for  REJECTING it. If you don’t, others will.

No6: Quantify it.

If whatever it is you’re explaining has some measure, you’ll be much better able to discriminate among competing hypotheses. What is vague and qualitative is open to MANY explanations. Of course there are truths to be sought in qualitative issues, but finding them is more challenging.

No7: Every link in the chain must work (including the premise)

If there is a chain of event or procedures that have to occur to arrive at a result they must all be reproducible, not just most of them. Even if one part of a chain can not be repeated then the result can not be trusted.

No8: Occam’s Razor always applies.

When faced with two hypotheses that explain the data/outcome equally well the SIMPLER one is usually always more correct.

No9: Is the hypothesis FALSIFIABLE?

Ideas and theories that are untestable are not worth much. Others must be given the chance to try and duplicate your experiments to see if they get the same result.


These simple rules fromSagan will help arm you against all the bull shit out there in the world, and there is a lot of bull shit. These rules will help you decide how ‘true’ or ‘accurate’ a ‘thing’ really is. They will help you when you are in a discussion with some pseudo-scientific shyster about how fascia is released with metal instruments, or an acupuncture needle deactivates a muscle knot and hopefully stop you falling for their crap.

And remember when you do question a pseudo-scientific shyster and they then turn on you for being too critical, skeptical, closed minded, negative, mean or nasty, remember this is just a common tactic to divert attention away from them and the discussion and try and spotlight you instead.

Don’t be fooled by it!

As always thanks for reading, and keep questioning everything!




  1. Hi Adam,
    Great post as per usual. I love reading and/or listening to anything by Carl Sagan. In my opinion one of the great minds, and well ahead of his time. As many of the great minds are.
    I used a Carl Sagan quote in a recent “Professional Issue” paper that I wrote as part of some study I was doing:
    “When Kepler found his long-cherished belief did not agree with the most precise observation, he accepted the uncomfortable fact. He preferred the hard truth to his dearest illusions; that is the heart of science.”
    It would be nice if of all our profession (and science generally) would adopt this approach to practice and research. Pleasingly some already do, but many don’t……as we can regularly see in the comments section on this blog of yours! 🙂
    Thanks again.

    • Thanks for your comments Mark, and yes cognitive dissonance is an unpleasent feeling for many. I know I have encountered it many times and am sure I will encounter it again!
      As you highlight questioning is at the heart of both science and philosophy, which I find myself becoming more and more engrossed in, which I never thought possible, especially philosophy.
      Many wont and don’t like it and resistance will be strong, but as both a nerd and a geek, I will use a quote from Star Trek…
      Resistance is futile!!

  2. I would add an additional rule: Claims made by people who benefit directly in tangible ways from those claims being believed to be true should be subject to extra scrutiny. This is why we require statements of financial interest by authors in published scientific papers.

  3. Have just started following you. I recently read your dinosaur paper. After starting to feel a little disillusioned with my profession it’s nice to find out that there are plenty of other people asking the same questions and challenging the accepted.

Related news