For several hundred years, the traditional Korean society was governed by a group of upper-class scholars, called “Seon-bi.” Most of them were confucian philosophers (i.e. humanists), who read and interpreted Chinese confucian classics. These humanist scholars developed unique confucian virtues: humanity, humility, persistence, noble will, and courtesy. They trained their minds to make their lives coincide with these virtues. Some of them considered mathematics and harmonics to be an essential component of the training of humanist scholars, but the majority of them considered science and technology as a practical knowledge and as such to be secondary and inferior, which should be cultivated by the middle, not upper, class. Since the early 20th century, a handful of new intellectuals learned Western science and technology. Although they emphasized the utility of science and technology for decolonial nation-building and modernization, they still felt that science and technology, as practical knowledge, was regarded as inferior to the humanities and social sciences in Korea. In this context, several notable scientists such as Tae-Gyu Lee, Jang-Choon U, and Hyung-Sub Choi articulated moral virtues inherent in science such as frugality, honesty, disinterestedness, curiosity, and patriotism. These scientific virtues were proposed in such a way to resonate with traditional scholarly virtues, and they served to show that scientific activities are not simply practical, but are also deeply ethical, which are necessary for post-colonial Korea.