In the preface to his early work Philosophie der Arithmetik, Husserl boldly announced his intention to make a contribution to that "desideratum of centuries,' a "true philosophy of the calculus' (PA 7).¹ Despite the title of the work, it was not arithmetic in the usual sense, but rather calculus or "analysis' itself — that great achievement of modern mathematics, and the field in which Husserl himself had received a doctorate several years earlier² — which stood at the center of his philosophical concern. The problems addressed in the work had occupied Husserl for several years prior to the publication of PA, and they would continue to be of interest to him until the very end of his career. In this study we will examine Husserl's treatment of these problems and of other problems which developed out of them. Prior to beginning our study of Husserl's own ideas, however, it will prove helpful to glance briefly at the historical context in which they arose.