Separating the Pseudo From Science
Say “pseudoscience,” and immediately a bunch of doctrines leap to mind: astrology, phrenology, eugenics, ufology, and so on. Do they have anything in common? Some posit unknown forces of nature, others don’t. Some are advocated by outsiders to the scientific community, while others have been backed by the elite. And the status of each can fluctuate over time. For millennia, philosophers have attempted to erect a boundary between those domains of knowledge that are legitimate and those that are anything but—from Hippocrates’ essay on “the sacred disease” (epilepsy) to editorials decrying creationism.
The renowned philosopher Karl Popper coined the term “demarcation problem” to describe the quest to distinguish science from pseudoscience. He also proposed a solution. As Popper argued in a 1953 lecture, “The criterion of the scientific status of a theory is its falsifiability.” In other words, if a theory articulates which empirical conditions would invalidate it, then the theory is scientific; if it doesn’t, it’s pseudoscience. That seems clear enough. Unfortunately, it doesn’t work. Epistemologists present several challenges to Popper’s argument.