The word "orthodoxy" is derived from a Greek word that means, literally, "right praise." A secondary meaning is "right belief."

Although the word "orthodoxy" does not appear in the New Testament, the concern for right belief was certainly present there (Romans 16:17; 1 Corinthians 11:2, 28; 15:1-3; 1 Timothy 1:10; 6:3-4; 2 Timothy 4:3; Titus 1:9; 2:1).

In the earliest centuries of the church, orthodox faith was expressed in creeds, especially the Apostles', the Nicene and the Athanasian. Other sources of orthodoxy include solemn conciliar and papal teachings, beliefs of the church that have been universally held down through the centuries, and the consensus of the Fathers of the church and its theologians.

The main practical criterion of orthodoxy is the liturgy, following the ancient Latin axiom: lex orandi, lex credendi ("The rule of prayer is the rule of belief").

Unfortunately, the word "orthodoxy" has taken on a polemical cast in recent decades. For certain ultra-conservative Roman Catholics, orthodoxy is implicitly identified with the neo-Scholastic theology that was dominant in Catholic catechisms and textbooks prior to the Second Vatican Council and also with the spiritual, liturgical, devotional and canonical practices of that same period.

It was a time when Catholics had no living memory or experience of significant change in the church's liturgical and sacramental rites. Indeed, there had been no changes, for all practical purposes, since the 16th century. The Mass and the sacraments were celebrated in Latin, with little or no participation by the laity.

It was also an era when Catholics gauged their catholicity and their fidelity to the church by things they did (attending weekly Mass, reciting the Rosary, defending the church against all criticism) and avoided (eating meat on Friday, practicing birth control, getting divorced, praying with Protestants) --- as well as their unquestioning loyalty to the pope.

The Second Vatican Council changed all this. It taught that the church is the whole People of God, not just the hierarchy and the clergy; that the church is bigger than the Catholic Church alone and that Protestants and other Christians are part of the Body of Christ as well, even if their degree of communion varies; that the liturgy and sacraments are meant to be understood and celebrated by all, laity as well as clergy; that the church is to be governed by the whole body of bishops and not by the Bishop of Rome alone; and that the church is always in need of renewal and reform.

The two popes and the many bishops who were leading figures at Vatican II represented the Catholic center --- the "orthodoxy" of the day, if you will: Pope John XXIII (now "Blessed John XXIII") and Pope Paul VI, and Cardinals Suenens, Döpfner, Marty, Liénart, Frings and Bea, Patriarch Maximus IV Sayegh, and various others as well.

All of them fully supported John XXIII's call for an aggiornamento (Italian, "updating") of the church. Their views and the documents they helped the council to fashion and adopt would have marked these men today as "progressives."

In comparison with the views of so many of their successors in the hierarchy, these Vatican II leaders might even have been dismissed nowadays as "dissidents."

But they were solidly "orthodox" and their program of renewal and reform was unhesitatingly approved by the two popes who presided over the council between 1962 and 1965.

Today, in a strange twist of events, many Catholics who promote the initiatives of the Second Vatican Council are regarded as "unsafe." Why? Because they are not uncritical of particular church practices and policies, do not regard the pope as the last word on any and every ecclesiastical topic, and believe that the laity should have more input in the governing of parishes and dioceses and the bishops more say in the governance of the universal church.

These Catholics welcomed the liturgical renewal mandated by Vatican II, and now resist efforts to set this renewal on a reverse course --- back to the pre-conciliar period when the emphasis was on "mystery" in the narrow (and erroneous) sense of the word, on clerical dominance in the rituals, and on adoration of the eucharistic species.

The restorationists, however, seek not only to rehabilitate the views of the council's defeated minority, but also to suppress those who stand with the council's majority. The spirit of the new "orthodoxy" is one of intolerance.

There are no gray areas. Only they deserve to be heard and read, or to occupy positions of pastoral leadership, or to determine what Catholic "fidelity" means and to "protect" the church from those who do not meet their particular standards.

But that is a recipe for division, not unity.

Father Richard McBrien is the Crowley-O'Brien Professor of Theology at the University of Notre Dame.