The task of condensing the History of the Church within a few hundred pages is a delicate one. We have undertaken it in the hope that our efforts will benefit both seminarians and college students. Our chief concern throughout has been clearness, precision, and brevity, and for this reason we have carefully eliminated unnecessary details. On the other hand, we have thought it our duty to stress the dogmatic controversies as well as the development of Christian institutions, and hence we have attached more importance to certain decisive epochs in the history of dogma. In this matter we willingly subscribe to the opinion of a very competent judge, who writes: "The history of the second and third centuries of the Church has its special interest, because of the sublime heights reached by so many holy emotions and passions, and because of the early confusion that reigned among a host of new and fecund ideas. But we must confess that the period of one hundred and twenty-five years, extending from the Council of Nicaea to the Council of Chalcedon (325-451), is far more important to one who would obtain a comprehensive view of Christianity, and that ignorance concerning the spirit of that time might lead one into serious error. In those days, in the midst of incredibly bitter doctrinal struggles, the authentic formulas of the great Trinitarian and Christological dogmas, which constitute the nucleus of present-day Catholic belief, took on explicit and definitive form." - Dom Charles Poulet, OSB, Monk of Solesmes, From the Preface