This essay examines the possibilities of being/becoming an ethical researcher in the academy. It tackles this task through the lens of an ethics application by Mary [pseudonym], a PhD student in sociology whose research thesis was investigating the reasons why married men with children use prostitutes. Two analyses are offered of Mary's story. The first analysis presents the sort of critique that a university ethics committee might make of Mary's ethics application and uses the principles that are the basis of regulatory research ethics frameworks around the world. From this starting point, the second analysis examines how the problems that an ethics committee would see in Mary's proposal might have come about. By way of explanation, I posit that an ethics of rational self-interest has asserted itself as a new moral economy among students, doctoral supervisors and within the management of universities. The co-existence of these two irreconcilable discourses of ethics--principlism and rational self-interest--has implications for being/becoming an ethical researcher and for the work of research ethics committees in the academy.