In the Edo period, the Neo-Confucian organic world view became popularized as the most sustainable conceptual framework for imagining the world, and it was against this ideological background that the concept of shokubun (a kind of responsibility) entered the mainstream. When the total world view of Neo-Confucianism unraveled with the arrival of the Meiji Restoration, therefore, it would hardly have been surprisingly if the concept of shokubun, too, ceased to play a historical role. In his translation of Samuel Smiles’ Self-Help, published in Japanese as Saigoku-risshi-hen in 1871, however, Nakamura Keiu used the word shokubun to translate the concept of “duty,” and the widespread reception of this work as the “gospel” of a new age breathed new life into the concept of shokubun. In this paper, I identify how the Neo-Confucian concept of shokubun differs from the concept of “duty” as used in Self-Help, and consider why Nakamura nevertheless equated the two and what the two different concepts had in common. As neither Smiles nor Nakamura systematically set forth their ideas, a rigorous comparison of the two concepts is difficult. Insofar as Smiles is concerned, therefore, I determine the characteristics of “duty” by using the insight provided by Weber into the Puritanism that prescribed duty. Regarding Nakamura, on the other hand, I focus on the “heaven” that provided the conceptual framework for understanding the “God” of Christianity, and attempt to understand Nakamura's concept of shokubun by comparing his concept of “heaven” with that of Kaibara Ekiken, which is thought to have informed his thought process and is actually touched upon in the philosophy of keiten aijin (“revere heaven, love man”). The points that emerge are as follows. Firstly, the subject of “duty” is the “individual.” At the same time, however, it is optimistically assumed that the individual performance of duty is directly connected to the welfare of the whole, and herein may be observed the Puritanist characteristics identified by Weber. Secondly, in the Neo-Confucian concept of shokubun in the Edo period, social order was conceptualized as being the concrete manifestation in human society of the organic harmony of the natural world. The subject of shokubun is a component of the whole order, in which respect it differs from duty. However, both share a similar optimism that this “ought” (Sollen) relates smoothly and directly to the order of the "whole.” Thirdly, Nakamura's thought is Neo-Confucianist in terms of its structuring of the correlation between heaven and man, which inherits the optimistic linkage of the moral cultivation of the individual with the peace of the whole world. Thus, through shokubun, one can simultaneously realize one's heaven-endowed nature and participate in the whole order. And fourthly, in terms of its content, Nakamura's thought goes beyond conventional Neo-Confucianism in that it abandons the ordering of interpersonal relations based on status, and incorporates instead the concepts of equality and philanthropy.