||Immanuel Kant argued for a transcendental, a priori, systematic foundation for science. In the Prolegomena to any Future Metaphysics, the Critique of Pure Reason, the Metaphysical Foundations of Natural Science, and other Critical (post-1781) works, Kant defends a "pure" (non-empirical), a priori philosophy of natural science, which extends to the famous statement in MFNS that only sciences with a pure, formal foundation are sciences at all. The neo-Kantian reception of Kant's work, especially by the Marburg School of neo-Kantianism (Ernst Cassirer, Hermann Cohen, and others) sustained interest in the Kantian methodology of science. Contemporary articulations and defenses of Kantian positions in the philosophy of science are eclectic. Some focus on Kant's defense of the mathematical method, and his theory of geometry: as one foundation for Newtonian natural philosophy, and as an independent science of space. Some focus on Kant's foundation for Newtonian mechanics. Early objections to such revivals of Kant's thought focused on the development of non-Euclidean geometry, on the rigorization of analysis, and on the challenges posed to Kant's accounts by relativity theory and by quantum mechanics. Many defenses of Kant and of neo-Kantianism in the philosophy of science appeal to the continuity or preservation of a priori reasoning in successive scientific theories. Recent appreciations of Kant on the sciences have expanded to the biological and other life sciences, including anthropology and psychology.