Ample attention is being paid in the higher education literature to promoting active learning among students. However, critical examination of educational purposes and ends is largely lacking in this literature on active learning. In expanding this debate, we consider it important to ask: "About what" substantive matters are students to be active? "To what end" is this activity directed, especially beyond gaining skills and competences within a unit of work or course? In this article, we critique and extend the conceptualisation of active learning. In particular, we discuss dimensions that are neither readily visible nor instrumental, which are overlooked in much of this literature. In doing so, we explore features and potential consequences of such an expanded conceptualisation. Drawing from educational philosophy and, in particular, existential philosophies, we show that active learning may also be partly invisible, unfocused, unsettling, and not at all instrumental--sometimes even leaving the learner more confused and (temporarily) incompetent. However, such forms of undisclosed or 'dark' learning, we conclude, are necessary and even vital counterparts for the forms of active learning that flood higher education curricula today.