This paper presents a critical analysis of student discourse on attrition as it unfolds in interviews on early departure from higher education. A synthesis of relevant studies and modelling done in the field shows that essential aspects affecting attrition and retention can be effectively conceptualized and acted upon in terms of the interplay between student and institution. These aspects were used in combination with James Gee's notion of Discourse models to design a unique framing for interpretation of interviews aimed at bringing out new causal dynamics that lie in this interplay. To illustrate this interpretation, Aristotle's notion of four causes is used. The analysis presented is a study of interviews with seven former physics students about their early departure. This framing of the analysis was necessary because the students' description of how they understood their actions did not explicitly reveal interplay between student and institution. These details lay behind a "wall of introspection" that otherwise posed a serious challenge to the use of student testimony as direct means to identify and address issues of early departure. The results are used to discuss research implications.