This book is a general introduction to metaphysics in four parts: The first part deals with metaphysics in general; in the second part the author deals with the first principles of metaphysics and truth; the third part deals with finite being and causes; and in the fourth part the author deals with infinite being, the existence of God, the essence and attributes of God, and the divine activity outside himself. Grenier was born in Gaspé, Quebec, and ordained for the diocese of Gaspé in 1924. He studied philosophy at the Angelicum in Rome (1924-1926), and at the major seminary in Gaspé (1926-1927). From 1927-1930 he studied theology at the Angelicum and Canon law at the Pontifical Lateran University. He held doctorates in philosophy, theology, and canon law. From 1930 to 1947 he was professor of theology at the seminary of Québec. In 1938 he was incardinated in the diocese of Québec. He spent a year in Oklahoma, 1944-1945. He was for many years professor of philosophy at the Université Laval.