The last few morceaux have dealt with the two types of authority which bishops exercise in the Church: their powers of holy orders and of governance (this last is also called the power of jurisdiction). This is how they lead the Church, and they do so in three broad areas: teaching, sanctifying and governing. In the last three, we’ve looked at the Church’s magisterium: that’s her teaching office, the first of these roles.
It’s no surprise that the Church exercises this role of teaching principally when expounding the core doctrines of our religion: the so-called “deposit of faith” that includes the identity of God, the Holy Trinity, Jesus Christ our Savior, and so forth. Our moral life – founded on the Ten Commandments and Jesus’ revelation of God’s additional desires for us – is also a central part of this teaching of the Church. Thus the Church’s magisterium is identified mainly with her teaching on what’s called in Latin fides et mores (“faith and morals” is the way this is commonly translated).
Yet God’s holy Church also teaches the best she can about everything else about which she is convinced she understands the truth which God wants us to know. Objective truth exists, but this is not always something we understand perfectly. Thus we can say, sometimes, that “doctrine develops.” The objective reality doesn’t change, but our understanding of it or the ways in which we best verbalize it often can and does change. The classic examples of this historically are the Church’s gradual realization of the immorality of slavery, and her shift away from suspicion of natural science to a wholehearted embrace of the finding of scientific community. Personally, I like the way that Pope St. John XXIII phrased it when opening the great worldwide meeting of bishops known as the Second Vatican Council in 1962: “The deposit of faith is one thing; the way it is expressed is another.” With this statement good Pope John assured not only the world’s bishops but us all that change in some things was always possible to consider: only the essential reality – the truth behind the phrasing – necessarily remains the same.