 Maritain’s work in the philosophy of nature appears throughout his work—in his Éléments de philosophie (Vol. 1, 1920, Introduction to Philosophy) and in an essay in Science et sagesse (1935, Science and Wisdom), but particularly in Les degrés du savoir (1932, The Degrees of Knowledge) and La philosophie de la nature (1935, The Philosophy of Nature). Again, Maritain’s account is based on Aristotle, Aquinas, and John Poinsot, though he clearly extends his predecessors’ views. 