"Freedom of religion" has always been a multi-dimensional concept with multiple meanings in the development of history. The various understandings of religion and freedom in different time, space and cultures create different views on freedom of religious belief. Therefore, the concept of "freedom of religious belief' is necessarily related to our reflection of theology, analysis of philosophy, and the discourses of law and politics. By issuing the Edict of Milan of Constantinus I Magnus (311 C.E.) and the Edict of Thessalonica of Theodosius I, the Church revealed the value of freedom of religious belief in life's journey with the "principle of tolerance." Both "Peace on Earth (Pacem in Terris)" issued by Pope John XXIII and The Second Vatican Council have identified the freedom of religious belief as a fundamental human right, namely, man has the freedom to choose any religious belief in accordance with his conscience. These key events-in history have been regarded as a turning point from tolerance to human rights, or from the objective truth to the personal right. The "Declaration on Religious Freedom" of The Second Vatican Council has evoked the following discussions: 1) Is religious truth secondary to man's free will and to his conscience? If so, then, 2) Is the fallible conscience which has the right to make mistakes proved by theological statements? 3) Is the "principle of tolerance" of Pius XII no longer valid after the Second Vatican Council, since no religious truths fi*om any religion possess the.priority? 4) Is the "Copemican Revolution" in the Second Vatican Council such an essential revolution that it has become a revolution of truth of faith? 5) Do the statements concerning freedom of religious belief from Gregory XVI, Pius IX and Leo XIII concord with the "Declaration on Religious Freedom"? This paper attempts to respond to these questions through history, analysis of the "Declaration on Religious Freedom," and reflections on theology, philosophy and politics.
