Among the chief causes by which it very greatly comes about that a great many, out of hatred for sincere truth, abuse the Acts of Chalcedon and the writings of Leo in order to abolish, or at least to diminish, the rights of the Apostolic See, this surely must be reckoned: that which proceeds either from a certain malicious interpretation of the ancient monuments, or from too little careful diligence in unrolling, examining, and comparing them together. For if, setting aside all partisan zeal, both theologians and treaters of ancient matters had been willing to debate the causes which we have resolved to handle, and to interpose judgment as the conditions of the age required, they would have brought the greatest light to certain obscure facts.
Then neither we nor other writers would have had to labor so greatly in detecting and refuting those fabrications which they themselves devised for hiding and suppressing the truth, in order to imbue and corrupt the minds of others with prejudices and false opinions. And so, since in the preceding Disputations I have endeavored to bring forth from darkness very many things which pertained to the author, the champions, and defenders of the Eutychian heresy — and since, moreover, I have treated more fully concerning the ecclesiastical judgments in the condemnation of Eutyches and the appeals of himself and others, clearly setting forth the supreme rights of the Apostolic See, and its custom in judging or re-examining causes even in the East, and very many other things of this kind —
I now understand that there remain for me to survey and review those things which finally were done against this same Eutychian faction at the Council of Chalcedon according to Leo's sentence; and the things which the same holy pontiff faithfully accomplished in the remaining course of his life for the good of the Christian commonwealth. I confess indeed that in composing the preceding Disputations I sometimes had a long discourse, from which the men of our age are wont to shrink, being accustomed to delight rather in the lighter rind of things than to exert themselves in the sincere investigation of those same truths. But many causes compelled me to this necessity of holding sometimes a more prolix discourse.
One of these arose from the practice of those lectures which over the space of many years I was accustomed to deliver in the schools of theology, in the weighing of which a brief and tight discourse can hardly be employed, lest the hearers be insufficiently instructed. For this reason I have been able only with great difficulty to overcome this habit acquired by long industry.
The other must be assigned to our adversaries, who, since they had stirred up certain obscure questions wrapped about with many cavils — which, given my present purpose in writing, I was bound to meet — it would have been utterly impossible to wrest away and refute their arguments in a few words; for very often it was necessary for me to appeal to the genuine sources and their interpreters, in order to demonstrate their ill-heaped and ill-constructed edifices and systems. Nevertheless, in the last part of these Disputations I shall strive altogether to pursue brevity, indicating or supplying some things by the aid of annotations; reducing others into a synopsis, with scarcely any engagement entered into with the adversaries;
and finally certain other matters which, given the magnitude of the questions and their difficulties, would remain to be said, and which have already been illustrated by certain men of the best faith and erudition, I have resolved to leave as it were untouched, referring our readers to those writers who have preceded us.