This paper argues, in an attempt at a unified account of negative polarity and free choice phenomena expressed by amu lany or wh-indefinites in Korean, English, Chinese, and Japanese that the notion of concession by arbitrary or disjunctive choice (based on indefiniteness) is crucial. With this central notion all the apparently diverse polarity-related phenomena can be explained consistently, not just described in terms of distribution. With strong negatives and affective licensors, their negative force is so substantial that concessive force need not be reinforced and the licensed NPIs reveal existential force. With free choice and generic-like items, licensed by modals, weakly negative in their natrue of uncertainty/irrealis, concessive force is reinforced and emphasized and the whole category denoted by the given Noun is reached in the process of concession by arbitrariy choice of its members on quantificational scale, giving the impression of universal force. The logical consequences of monotone decreasingness are transparent with strong negatives but less so with weaker ones. Negative polarity, free choice, genericity, concession, arbitrary choice, indefiniteness, scale, Korean, English.