SAMUEL J.THOMAS* For much of the world, the work of the Catholic bishops and periti (experts) at the Second Vatican Council (1962-1965) collectively signaled the end of a four-hundred-year-old siege mentality, the beginnings of a positive engagement with modernity, and a generally more tolerant, open, and collegial church. In fact, it has become a truism that the Council Fathers generated documents strongly affirming Pope John XXIII's call for church renewal (aggiornamento). Yet, less than a year after the Council's final session, a Vatican initiative occurred that seemed at odds with the Church's new public image. At the very least, the intervention was a sign of Rome's growing concern over the nature, pace, and extent of renewal, and of its resolve to tighten the reins and exercise more direct control. This episode began when Alfredo Cardinal Ottaviani (1890-1988), the conservative prefect of the Sacred Congregation for the Doctrine of the Faith (CDF), sent a secret circular letter dated July 24, 1966, to the heads of all Catholic episcopal conferences.1 He reminded the world's bishops that they must carefully monitor Church renewal so that errors the interpretation of the Council's decrees could be prevented or stopped. The Sacred Congregation, its role as the Vatican's official guardian of the faith, would provide the oversight and guidelines for achieving those ends.2 Ottaviani's letter was a significant expression of a concerted effort by the Vatican to ensure orthodoxy the atmosphere of freedom and change that characterized the immediate aftermath of the Council.3 How did America's Catholic bishops respond that heady atmoshpere? In order to andwer this question, a more focused inquiry will be necessary, one that probes the bishops' self-image after the Council: more precisely, how soon and how earnestly did they act on the Council's rather resounding declarations of their collegial relation to the Holy See and to one another? One answer has already been given by Father Gerald Fogerty toward the end of his cogent analysis of the relations between The Vatican and the American Hierarchy from 1870 to 1965. After criticizing the bishops' relatively minimal involvement the Council's reconsideration of the doctrine of collegiality, Fogarty added this assessment of their behavior in the years after the council: Only gradually...did the...bishops begin to see what their predecessors had seen: that true loyalty to the Holy See might mean a respectful representation based on experience.4 It has not been possible, until recently, to begin a systematic examination of Fogarty's hypothesis regarding the bishops' postconciliar behavior, primarily because of the inaccessibility of pertinent archival collections dealing with Vatican-American hierarchical relations after 1965. In the late 1980's and early 1990's, however, an act of unusual openness and courage, valuable archival materials among the papers of Alexander Zaleski, Bishop of Lansing (1965-1975), were opened to scholarly inquiry. The following study, based largely on those materials, argues for a modification of Fogarty's assessment: It shows that an early and significant case of postconciliar Roman intervention, that is, the letter from Ottaviani, the American hierarchy displayed a willingness to test the strength of its authority and the persuasiveness of its collective pastoral experience. More specifically, the thesis of this essay is that the American bishops' reply to Ottaviani's letter, and the leadership that was exercised coordinating that reply, not only sustained a spirit of unity with the Holy See and incorporated a cautiously optimistic attitude toward renewal, but also exemplified the more participatory mode of episcopal collegiality that had emerged from the Second Vatican Council.5 To place this episode a broader context, and more clearly to delineate the milieu within which the American Catholic Church was beginning to take on its postconciliar stripes, it is important to recognize at the outset that both the letter and the bishops' reply occurred at a time when numerous Vatican instructions, decrees, and published addresses on church reform, authority, and dissent were directed toward a variety of national and international audiences. …