Post modern thought is to take a category that has been taken for granted and say, what happens if we mess with it a little. Sometimes categories aren't that robust, especially if you look at things in a historical trajectory. What counts as mad is pretty different a overtime. And we can learn something about how we think about our the own way we deal with people that we now call mentally ill. But there are lots of bad examples too.
Everyone has heard of the term “pseudoscience”, typically used to describe something that looks like science, but is somehow false, misleading, or unproven. Many would be able to agree on a list of things that fall under its umbrella — astrology, phrenology, UFOlogy, creationism, and eugenics might come to mind. But defining what makes these fields “pseudo” is a far more complex issue. Given the virulence of contemporary disputes over the denial of climate change and anti-vaccination movements — both of which display allegations of “pseudoscience” on all sides — there is a clear need to better understand issues of scientific demarcation. Shermer and Gordin explore the philosophical and historical attempts to address this problem of demarcation.