This book takes us from the early childhood to the last days of George Lemaîitre, the man behind the theory of the primeval atom, now better known as Big Bang theory. But who was George Lemaître? A clergyman, a genius astronomer, an audacious cosmologist, a computer enthusiast ahead of his time, a professor with his head in the clouds, a bon vivant mathematician and gourmand? Dominique Lambert's book peels away these layers, chapter by chapter, from the adventures of a boy from Charleroi (Belgium) who became Monseigneur Lemaître as well as his impact on contemporary cosmology. The reader will follow Lemaitre's works through the course of his life, discovering along the way his involvement with the Chinese student community, his complex relationship with the Vatican, his deep devotion to the University of Louvain, his friendship with figures such as Einstein and Eddington, his adventures through the two World Wars, his travels in America, his curious interest in Moli're and his deep faith lived through the "Amis de Jésus". The resulting picture is of a remarkable figure who was sensitive, creative, meticulous and, paradoxically, both discreet and exuberant while also being a man of exceptional integrity who reconciled his science with his faith. More than a book on one person, this biography of Lemaître offers the key to a better understanding of the profound changes which took place in the fields of science, faith and academic life in the last century. About the Author Dominique Lambert holds PhD's in Physics and Philosophy from the Université Catholique de Louvain. He is currently professor at the University of Namur (FUNDP) and a member of the Académie Royale de Belgique (Class of Sciences). His work focuses on the philosophy and history of science as well as on the relationship between sciences and theology. The director of the Department of Philosophy at the University of Namur, he also conducts research within the Namur Center for Complex Systems (naXys).