 Maritain’s philosophical work came to be more eclectic, with the publication of books on Thomas Aquinas (1930), on religion and culture (1930), on Christian philosophy (1933), on Descartes (1932), on the philosophy of science and epistemology (Distinguer pour unir; ou, les degrés du savoir, 1932) and, perhaps most importantly, on political philosophy. Beginning in 1936, he produced a number of texts, including Humanisme intégral (1936), De la justice politique (1940), Les droits de l’homme et la loi naturelle (1942), Christianisme et démocratie (1943), Principes d’une politique humaniste (1944), La personne et le bien commun (1947), Man and the State (written in 1949, but published in 1951), and the posthumously published La loi naturelle ou loi non-écrite (based on lectures delivered in August 1950).