In architectural design education, students develop drawing, conceptual, and critical skills which are informed by their ability to reflect upon the production of ideas in design processes and in the urban, environmental, social, historical, and cultural context that define architecture and the built environment. Reflective actions and thinking are therefore inherent in the education of the architectural designer and in the individual student's experience of inhabiting the built environment. This paper explores these reflective modes of production in order to challenge the determinism in spatial thinking that persists in formalist approaches to architectural theory and design. Part I examines how Kant's theory of reflection in the "Critique of Judgment" (1790) is valuable for a discipline that requires both geometric and spatial reasoning in its design processes, suggesting that the reflective subject enables internal and embodied experiences of space. Part II considers the role of reflective judgment in three examples (or "subject-figures") of architectural design education, exploring how it informs a student's active development of aesthetic and technical judgments. The discussion therefore explores how Kant's philosophy may reconnect the reflective subject and the geometric figure through the embodied activities of inhabiting, drawing, and theorizing architecture. (Contains 26 notes.)