This study theoretically examines the consilient themes of the discourses addressed in the classes of “writing by discipline.” Discipline-specific writing has the advantage of easily motivating students to learn. However, there is also a risk that writing classes that should hone the language of public discourse may will focus only on practical language for each discipline. Thus, this study explores discursive topics that can be differentiated by discipline and can also be consilient through public language. This study examines the ideological question, “Do humans exist as individuals or as a society?” as a topic that can be addressed in a writing class of the humanities and social sciences department. As a science and technology topic, it examines the question, “Is science and technology the exclusive property of individuals or society?” Furthermore, as a medical topic, it examines the question, “Do life and the body belong to the subject or to others?” Finally, even though they are differentiated in this way, we theoretically explore the point where they are ultimately consilient through the question of modernity, “the subject or the other?” The point at which the questions of modernity are differentiated gives rise to discourses that can inspire special learning motivation for each discipline. However, the point of consilience is the point where these can be elevated to universal, contemporary public discourse. This is because it is a broad, reflective question posed by modernity in our time. Therefore, the questions that this study explores will be suitable as a discursive topic through which contemporary writing learners can fundamentally reflect on the specificity and universality of their discipline.