The Church is commissioned to teach the morality of the Gospel, which is the moral revolution of Christian love. The New Testament reduces all morality to the commandment of love. This implies no commission to teach philosophical morality, although moral doctrine must be formed by the use of reason. Reason, however, must operate within the morality of Gospel love, not outside it. The place of reason in the Christian life is to ascertain how to implement the love that Jesus reveals, not how to render it nugatory. If authority solves a moral problem by philosophical reasoning rather than by the application of Gospel love, its position has no more strength than its philosophical reasoning. It will be as strong or as weak as that of the ecclesiastical commission that met to settle the question of whether the sun moves around the earth.
-Rev. John L. McKenzie, Catholic Theologian, Biblical Scholar
Authority in the Church