 Although Maritain did not produce a text that provided a comprehensive statement of his metaphysics, his major contributions to the area are found in Sept leçons sur l’être et les premiers principes de la raison spéculative (1934, A Preface to Metaphysics: Seven Lectures on Being), the Court traité de l’existence et de l’existant (1947, Existence and the Existent) , and De Bergson à Thomas d’Aquin, essais de métaphysique et de morale (1944). Discussion of his metaphysics are also found in other works, such as Distinguer pour unir; ou, les degrés du savoir (1932, The Degrees of Knowledge), Science et sagesse (1935, Science and Wisdom), Ransoming the Time (1941), and Raison et raisons (1948, The Range of Reason).