Philosopher Karl Popper famously asked how to tell the two apart. His answer—falsifiability—hasn’t aged well, but the effort lives on.
Where do you place the boundary between “science” and “pseudoscience”? The question is more than academic. The answers we give have consequences—in part because, as health policy scholar Timothy Caulfield wrote in Nature last April during the first wave of COVID-19, “tolerating pseudoscience can cause real harm.” We want to know which doctrines count as bona fide science (with all the resulting prestige that carries) and which are imposters.
The demarcation problem is no less central today than it was when Popper broached it. But the solution is not at all obvious.
This is the “demarcation problem,” as the Austrian-British philosopher Karl Popper famously called it. The solution is not at all obvious. You cannot just rely on those parts of science that are correct, since science is