Paul Hoyningen-Huene argues that what makes scientific knowledge special is its systematic character, and that this can be used to solve the demarcation problem. He labels this STDC: “Systematicity Theory’s Demarcation Criterion.” This paper argues that STDC fails, because there are areas of intellectual activity that are highly systematic, but that the great majority of scientists and historians and philosophers of science do not accept as scientific. These include homepathy, creationism, and climate change denial. I designate these activities “facsimile sciences” because they mimic the appearance of science but are not, by the standards of philosophers and scientists, scientific. This suggests that we need additional criteria to demarcate science from non-science and/ or nonsense. © 2017 Springer Science+Business Media B.V.