This article focuses on describing the interplay between teaching and learning practices in Higher Education and the disciplinary context of such practices. In particular, it aims to address the question of how course design, teaching, and learning activities take place within a particular academic culture and how those activities mutually shape each other. To do so, we propose to use the notion of mediating actants, a combination of Vygotsky's (1978) notion of mediation with the concept of "actant" that is at the core of actor-network theory (ANT). We suggest that such a notion can be useful in understanding the processes of construction of teaching and learning within disciplinary discourses and practices. This article is based on an empirical study of three Master's programs at a Scandinavian institution of higher education. Data was gathered using ethnography-inspired methods such as interviews, observations and document analysis. In our analysis we identified six elements as central in how quality teaching and learning are constituted within master's programs: (1) the master's thesis, (2) writing as a mode of thinking (3) the students' learning environment, (4) the teaching process and teaching style, (5) the students' conceptions of learning and their engagement, and (6) the processes of transformation from spontaneous to scientific concepts that the students undergo.