This paper aims to argue that, although the issues of interdisciplinary research are often said to arise from language translation problems among multiple disciplines, the essential problem is competing sets of codes of ethics among communities. Such competitions lead to different criteria of evaluations of "good arguments," which in turn causes failure of sharing assumptions when complementing implicit assumptions according to the principle of charity. In general, each discipline, with its peculiar knowledge as well as codes of ethics, is justified not to apply logical principles when priority is put to sustain the community.