The role of the Church in law is dynamic. For the early Christian community, law was often a tool of oppression wielded by the state, though it was occasionally used to challenge arbitrary state power by leaders who had access to citizenship and education such as the Apostle Paul. Once states (particularly the Roman Empire) formally endorsed Christianity, making it the official religion, the Church’s approach to law shifted from a posture of critique to one of power and justification. Although states and the contexts in which they governed did not remain static, it is arguable that the Catholic Church generally continued to imagine law as a tool that it could legitimately use to encourage conformity with its teaching. The Reformation and the rise of modern nation states challenged this identification between states and the Catholic Church, gradually shifting the Church’s posture back to one of defense and critique. However, this was not a reversion to the marginalization of the early Church. Instead, it gave the Church the opportunity to consider and comment on the policy implications of its teaching, especially its social teaching, without the power to enforce its doctrine on states. Ideally this gives Church institutions and Catholic scholars freedom, objectivity and moral authority to proffer arguments for the appropriate place of law in fostering the common good. In this project, we rely on authoritative expressions of Church teaching, and we apply a variety of methods rooted in our tradition and the best of contemporary science and social science. If the Mirror of Justice is a fair example of the development of Catholic legal theory, it is obvious that it represents a diversity of views, which are sometimes in opposition. Even so, we rely on the same body of texts and traditions, and we endeavor to engage legal problems in ways that are faithful to our commitments to Christ and the Gospel. We strive to engage each other and the world in a spirit of humility, motivated by love.
What is the law of the People of God? It is the law of love, love for God and love for neighbour according to the new commandment that the Lord left to us. It is a love, however, that is not sterile sentimentality or something vague, but the acknowledgment of God as the one Lord of life and, at the same time, the acceptance of the other as my true brother, overcoming division, rivalry, misunderstanding, selfishness; these two things go together. Oh how much more of the journey do we have to make in order to actually live the new law — the law of the Holy Spirit who acts in us, the law of charity, of love! Looking in newspapers or on television we see so many wars between Christians: how does this happen?[ …] We must ask the Lord to make us correctly understand this law of love. How beautiful it is to love one another as true brothers and sisters. How beautiful! Let’s do something today. (Pope Francis I, 6/12/13)