This is Part 4 of a 5-part series that I am writing on science and PT practice. If you have not read Parts 1 – 3, do that first before reading any further…

So “Falsifiability and The Flaming Laser Sword” sounds like a new Harry Potter book. Maybe that is how Lord Voldemort lost his nose… Wait, what was I talking about?

Oh yeah, science! So we talked about how Descartes showed that we cannot know anything is true with 100% certainty. We also looked at the limitations of inductive reasoning, Continuity of Nature, and Ockham’s Razor. So when an idea holds up to these tests alone, there is still plenty of room for doubt. As a matter of fact, most things known to be pseudoscience will hold up quite nicely against these tests. So what can we really know?

Well, we can’t prove that something is true, but what about proving that something is false? This gets to the idea of “falsifiability” as defined by Karl Popper in the early 20th century. In order for something to be considered scientific, there must be an example that, if found, would falsify the idea. Confused? Let me clarify.

Let’s take the statement “All swans are white.” Now, with Continuity of Nature we would go around looking for white swans in order to support that statement. You are inferring a general rule from a number of individual cases (similar to a case series in medical research). You are looking to confirm the idea, which we have shown to be impossible. This is the heart of The Problem of Induction. It is also known as confirmation bias.

But what if we spent our time looking for a swan that was NOT white? Simply finding ONE example will very simply falsify the statement “All swans are white.” This is the goal of experimentation – To falsify, not to confirm. The very important point here is that although you can only INDUCE confirmation (uncertain), you can DEDUCE falsification (certain). Popper brought deduction back to the table after Descartes removed it over 300 years ago. You can use induction to come up with ideas, but they must be falsifiable in order for them to be scientific.

Einstein (pretty smart guy I hear) put it best. “No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

So what about Descartes’ Evil Demon? You can never prove that the Evil Demon does not exist. That’s right, you cannot falsifiy that idea, therefore it is not science. This makes the Evil Demon irrelevant in scientific discussions. POOF! He’s gone. Pretty cool, huh?

We defined a philosophical razor as a tool to define or categorize ideas. Popper’s Falsifiability is such a razor. But razors are small subtle instruments. The term “razor” does not convey the true power of the this tool. So the science philosopher Mike Alder didn’t refer to falsification through experimentation as “Popper’s Razor”. He called it “Newton’s Flaming Laser Sword”. If you have time, I strongly encourage you to read his entire article.

(Side note: Just like William of Ockham was never quoted to state what is now known as Ockham’s Razor, Newton himself never defined falsification though experimentation. He was, however, one of the first to famously engage in the practice. He was known for it and is now better known than Popper. Sorry Karl.)

What the Flaming Laser Sword does is provide a razor sharp demarcation of science. The question that must be asked is, “Can we objectively challenge the idea?” If we cannot, then it is not science. Another thing that I would like to stress here: An unfalsifiable idea could be 100% right, it simply is not science. Technically, the scientific position is “No comment.”

History has shown that these unfalsifiable ideas rarely hold up over time so personally, I almost always take the skeptic’s position. In science this is known as “the null” – the stance that an idea is NOT true until properly tested for falseness (that is actually a word – go figure!).

This is why religion and politics create such heated debates. Just about every statement COULD be true depending on perspective and confirmation bias. If it was wrong, you couldn’t prove it. So people try to speak more loudly, passionately, confidently, and “expertly” about what they can induce. Sound familiar? Listen to people in the PT profession talk about the treatment of non-specific pain…

Continue to the final post, Part 5: Seppuku and the Tooth Fairy.