Few people keep such a close eye on so-called alternative medicine (SCAM) as Dr. Edzard Ernst. His life’s work promotes critical thinking and demonstrates through evidence and logic that SCAM doesn’t work. His latest book, Bizarre Medical Ideas … and the Strange Men Who Invented Them, is a natural extension of his legacy. An encyclopedia of alternative medicine, the book highlights the people behind the invention, promulgation, and continued promotion of these ideas.

The book is filled with cautionary tales demonstrating the hazards that follow from limited critical thinking skills, conspiracy thinking, and delusions of grandeur. A common theme is that many types of alternative medicine are rooted in seemingly small and simple errors that many people make, such as confusing correlation with causation, accepting only confirmatory evidence, and moving the goal posts.

Example anecdotes from the book include:

• Reflexology: William Hope Fitzgerald made and influenced many claims about reflexology, which has been claimed to lead to better relationships; better cardiovascular circulation; and improved mental, emotional, and spiritual balance and stability—and it all comes from your feet!
• Gerson Therapy: Max Gerson’s story helps us see where the panic about processed foods, cancer diet culture, and coffee enemas for health originates.
• Alexander Technique: Frederick Matthias Alexander demonstrates why the “it worked for me!” conclusion needs to be tested and should not just be put into practice and marketed. He seemed to be the modern health coach of his day.
• Homeopathy: Samuel Hahnemann’s story alone provides a solid example of being too attached to one’s ideas, ignoring evidence to the contrary, and refusing to understand how the physical world works.

While I enjoy a good book of science-related parables as much as the next skeptic, Ernst goes one step beyond merely providing the background of these people and their ideas. He’s designed a scale to measure alternative medicine ideas, The Humbug Score, and applied it to all the stories. The Humbug Score is bound to become the rubric by which skeptics measure all ideas, not just those in the medical realm. It encompasses important aspects such as absurdity of the concept, use of intuition, failure to produce evidence, rejection of evidence, and conspiracy theories. Every idea gets a score (0–2) in twelve areas, and the total is added together. The “perfect” Humbug Score is a twenty-four, reserved for the most egregious ideas, such as radionics. The lowest Humbug Score included in the book was for autogenic training, which earned a nine.

Ernst doesn’t provide classification categories or cut-off scores for when an idea should be definitively determined dubious, but that’s not the point of the Humbug Score. The scale itself isn’t supposed to be scientific in the literal sense. Rather, it’s an additional way to articulate the degree to which an idea is bizarre. It’s also meant to demonstrate that sometimes even seemingly preposterous ideas can be useful. This gets to the heart of the demarcation problem (i.e., the sometimes blurry line between science and pseudoscience), supporting our critical thinking skills and keeping us open minded. If we go where the data lead us, we can end up in unexpected places. The Humbug Score allows us to see why we shouldn’t always throw the baby out with the bath water.

This is not to say that every idea should be taken seriously and require that time, energy, and resources be devoted to research. Ernst is a staunch proponent of the premise of prior plausibility, and that comes through in the book. But he also spends time thinking about the possibility that just because an idea didn’t germinate from an expert doesn’t necessarily mean that it can’t be important.

While it’s helpful to include the Humbug Scores, I have no doubt that they will also become a badge of honor for some practitioners of alternative medicine: “I scored a perfect twenty-four on Ernst’s Humbug Score!” For example, I believe Albert Abrams would have delighted in the perfect score he earned for radionics. It’s only a matter of time before the score is weaponized and used to market alternative medicine.

Ernst, himself a physician, has chosen to highlight many physicians who stepped out of their training and expertise. These tales are to be used as a warning, especially to those who practice medicine. While society may hold doctors on a pedestal, that is not to say that they know everything or always have good ideas. Ernst’s book demonstrates what can happen—and why it’s dangerous—when anyone, but especially physicians, become so enamored with their own cunning, intelligence, and ideas that they forget to ask the question “Is it even feasible?”