 Zhu Xi had a “particularistic” tendency to investigate each phenomenon on its own terms, without attempting to relate it to more general explanatory principles, as in his treatment of inertia and the relativity of motion. In another case, he discussed the difficulty of boiling rice atop a particular mountain in terms of the characteristics of the qi (cosmic vapor) of that mountain, without relating the phenomenon generally to characteristics of qi (as air pressure) at high altitudes. Inevitably, this ignoring of general principles made Zhu less sensitive to the contradictions that arose when he offered more than one explanation of a single phenomenon.