This paper explores the emergence of the distinctions between the transcendental and the psychological and, correlatively, between phenomenology and psychology that emerge in The Idea of Phenomenology. It is argued that this first attempt to draw these distinctions reveals that the conception of transcendental phenomenology remains infected by elements of the earlier conception of descriptive psychology and that only later does Husserl move to a more adequate—but perhaps not yet fully purified—conception of the transcendental.