This study aims to seek a new approach of educational method to enable students to cultivate ethical mind as professional engineers through strategically designed course program including persuasive essay writing. On the assumption that the social psychology theories of ‘role-taking’ and ‘attitude change’ derive effective basis to practice such education programs, the study develops a theoretical framework for education, a syllabus of the class and a series of short essay questions to exercise cognitive abilities concerned with ethical practices. Findings from qualitative data analysis of descriptive texts by students show that this framework succeeds in providing effective training opportunities, in which students try to learn how to construct social attitudes for ethical decision making within difficult and complex situation overcoming conflict between opposing factors such as individual and organizational value. In conclusion theoretical and practical implications of the study combining modern ethics and cognitive science would be discussed.