 Kant’s conception of mathematics was debated by his contemporaries; influenced and provoked Frege, Russell and Husserl; and provided inspiration for Brouwerian Intuitionism. His conception of mathematics was rejuvenated as worthy of close historical study by Gottfried Martin’s 1938 monograph Arithmetik und Kombinatoric bei Kant (Martin 1985). Despite the very different positions that contemporary commentators develop as to how best to understand Kant’s thought, they are broadly united in opposing a long-standard story (perhaps originally promoted by Bertrand Russell in his Principles of Mathematics and by Rudolph Carnap in his Philosophical Foundations of Physics) according to which the development of modern logic in the 19th and 20th centuries, the discovery of non-Euclidean geometries, and the formalization of mathematics renders Kant’s intuition-based theory of mathematics and related philosophical commitments obsolete or irrelevant. Contemporary commentators seek to reconstruct Kant’s philosophy of mathematics from the vantage of Kant’s own historical context and also to identify the elements of Kant’s philosophy of mathematics that are of eternal philosophical interest (Parsons 2014).