In medical science, one must pay attention not to plausible theorizing, but to experience and reason together.
— Hippocrates
The James Randi Educational Foundation has not validated any extraordinary human ability; ergo, none is likely to exist.
— Anonymous crank
Are psi and other forms of mental kung fu real? Some research suggests that they are, but to properly evaluate the data, you need a solid background in experimental design, statistical probability, and the subject itself. Science is hard.
Supposition and common-sense appeals are easy, and unlike research data, they always support the desired outcome. A suitable bit of folk wisdom can be found to justify any emotional investment.
For example, if you want to master a difficult new skill, you’ll remember that practice makes perfect; later, if you become frustrated and finally give up, it is only because you can’t teach an old dog new tricks. This is all ex post facto rationalization—not reason, and certainly not science.
So belief and disbelief are not two poles on the spectrum of opinion, or two sides of the same coin. They are both on the same side of the coin. There is nothing inherently rational about a default to skepticism, it’s just another bias.
Maybe we can do better than that.