The Apologia is undoubtedly one of the greatest literary and spiritual classics. The author tells the story of his conversion, starting from his childhood experiences until he finally – after years of study and consideration – joined the Roman Catholic Church with conviction. As an Anglican theologian at the University of Oxford, he initially fought against the incipient liberalism in his church. Through his study of the Church Fathers, John Henry Newman began to study the basic principles of the faith. He published tracts to establish the conservative Anglican faith but was vigorously attacked by the bishops. As a result, he gave up all offices and retired to Littlemore. In a long and profound process of thought, John Henry Newman realizes that only the Roman Catholic Church, with the developments in doctrine, is based on the teaching of the early Church. This was the beginning of his conversion to the Catholic faith. He reports in a documentary account of the whole tragedy of his conversion. With meticulous care, the author lets the sources speak. This work reveals John Henry Newman as a sensitive, reserved and great thinker.