Abstract
This chapter examines the role and need for ethics in mathematical practice. Mathematics is one of the few areas of study in which ethics is widely perceived as irrelevant. Many mathematicians and others resist the idea that we need to consider the ethics of both pure and applied mathematics. The foundations of this resistance are analyzed and located in background philosophies and ideologies of purism and neutrality. The range of social practices is investigated, and different ethical problems and issues are brought to light. It is argued that virtuous mathematicians can legitimately pursue mathematics for its own sake, but as citizens they also have a responsibility to care about the social impacts of mathematics. A review of the literature on the social responsibility of science and mathematics reveals that, although long neglected, concerns about the ethics of mathematics are starting to emerge in publications and training practices. Some of the more ethically sensitive areas are explored and three problematic categories are distinguished and exemplified. These are (1) mathematics in public communications, (2) overt applications of mathematics with powerful social impacts, and (3) the hidden performativity of mathematics in restructuring society, institutions, and social practices.