We argue that an epistemology of martial arts is at least as complex as advanced epistemological positions available to the philosophy of science. Part of the complexity is a product of the epistemic relation between the knower and known, or the scientist and the object of inquiry. In science, we measure things without changing them and, sometimes, complex systems can change as we measure them; but, in the epistemology of sport that we are interested in, each measurer is also an (...) object of inquiry. As such, each martial arts practitioner has to use various epistemic tools to measure a responsive system. We proceed in three steps. First, we discuss three epistemological frameworks in the philosophy of science—perspectivism, productivism, and distributed cognition. Second, we develop an epistemology of martial arts that features components from each of those epistemic frameworks. Third, we close the paper with a brief discussion about the unique complexity available to the martial artist, focusing on the responsive measurements that occur between two systems. (shrink)