Context: Josef Mitterer’s non-dualism advocates a method of analysis as distinct from a metaphysical position. As such it bears resemblance to my earlier work. Problem: Is there only the world of discourse or is there a sense in which some facts and some theories are beyond argument and will remain so? Approach: In my analysis I try to apply Mitterer’s ideas to science, philosophy, and literary criticism. Results: I claim that it is not possible to argue against certain scientific facts or against scientific progress. The same holds for philosophy and literature. Implications: Some claims about science appear to be inconsistent with Mitterer’s non-dualist model, according to which validity-claims are limited to interpretations. Also, in literature, Mitterer’s claim that “text is neutralistic” does not apply.