While reading Scientific American a few days ago, I came upon a quote by Christopher Hitchens, "What can be asserted without proof can be dismissed without proof." This quote is simple yet powerful. If someone makes an assertion that is not supported by evidence, we have the right to reject it without providing evidence.
This idea is related to Bertrand Russell's teapot, a concept first coined by the philosopher Bertrand Russell to illustrate the fact that the burden of proof lies upon the person making scientifically unfalsifiable claims. Russell argued that if he claimed that a teapot were orbiting the sun, it would be nonsense for him to expect others to believe him just because they could not prove him wrong.
In a piece titled, "The Neurology of the Spiritual Experience," an essay in hypertext by Scott Bidstrup, he argues that, "If no metaphysical explanation is required to explain your experience, your 'evidence' is no longer evidence of anything metaphysical." In other words, if a vase falls over in another room, this is not proof that a ghost was responsible if we see a fluttering curtain over an open window that is within range of the vase. Since a fluttering curtain is a known cause for such an event, there is no need to call upon the supernatural for an explanation.
In his essay, Scott Bidstrup summarizes several neurological studies that show how the brain can be artificially stimulated to experience a feeling of spirituality and divine presence. Since such experiences can be produced in the laboratory, again, there is no need to call upon the divine. Some may argue that a deity acts on the brain to create this sensation. Making that claim is logically equivalent to asserting that the flip of a light switch does not release current that powers a light (a known scientific process), but that the phenomena is magic (an unfalsifiable assertion).
As I have written in other posts, I have a strong desire in learning the "truth" without succumbing to the common pitfalls associated with wishful thinking and confirmation bias. The above principles provide examples of simple ways of assessing claims. The scientific method provides an additional arsenal of tools to test assertions that are falsifiable.
I spend lots of time reading articles that illustrate examples of debunked claims, (See, for example, The Skeptical Inquirer, which is an excellent source of information on studies of the paranormal, medical quackery, scientific fraud, etc.) Not only are there many excellent articles that show how logic and controlled experiments can be used to get the real story, there is also a large scientific knowledge base on how the mind can fool itself.
After reading articles on such topics over many years, a picture of the truth slowly comes into focus. For example, there are many well-designed experiments that show that acupuncture does not work as claimed. There are two main issues. First, there are no physiological structures that connect the purported cause with the effect. In other words, there are no mechanisms nor physical pathways that would explain why placing a needle in the foot would relieve the pain of a headache. We understand the network of nerves that transmit information about pain, and there is no conceivable way that acupuncture can work. This alone, however, is not proof against the efficacy of acupuncture.
A series of elegant experiments were performed that fooled patients into believing that they had been administered acupuncture, but, the skin was never punctured. The researchers used trick needles that were in reality dull collapsing rods. Even so, patients reported feeling relief from pain - clearly, a placebo effect. All studies that are carefully controlled for both researcher and patient bias always show a negative result. All of the studies that have shown positive effects were later found to be flawed experiments.
The preponderance of evidence shows that acupuncture is ineffective. When people try to convince me otherwise by alerting me to studies that show a positive correlation, these studies are invariably the ones that have already been found to be flawed. At this point in my life, I do not have the time nor energy to argue with such people. I usually point out that all of the evidence discredits the efficacy of acupuncture and that I prefer to discus a more interesting topic. Accusations follow that I am closed-minded and arrogant.
There are many wacky things that are believed by even intelligent people. It may sound arrogant when scientists appear to pompously reject such ideas, but at some point, enough is enough. Though we may be arrogant to some extent, I do not believe that we are closed minded. When new evidence is produced, our profession demands that we accept it on its merits. When ideas that I believe to be wacky are proven right, I will gladly change my mind. Until then, pardon me for appearing arrogant...