As even its defenders admit, reflection in education suffers from a lack of conceptual clarity. In this essay, Henk Procee provides a philosophical analysis of the central concepts in this domain. In the current literature, these concepts are usually taken from the pragmatic school of John Dewey and from critical social theory associated with Jurgen Habermas. In contrast, Procee argues that Kant's philosophy incorporates ideas better suited to understanding reflection in education--particularly through his distinction between understanding ("Verstand") and judgment ("Urteilskraft"), a distinction that supports an epistemology that accepts the special nature of reflection as judgment as opposed to formal learning (which, in Kant's analysis, is part of understanding). In addition, Procee discusses some consequences for the aims and methods of reflection in education.