The Preface of the Book, in which he investigates the History of the Jewish Nation; Mention of those who began such a Work; how and from what Sources he collected his History; how he was intent upon the Truth, and what other Details the History will contain
Let not an impertinent or malignant spirit be imputed to me, for having dwelt upon the disputes of ecclesiastics among themselves, concerning the primacy and the pre-eminence of their own heresy. In the first place, as I have already said, an historian ought to regard everything as secondary in importance to truth; moreover, the doctrine of the Catholic Church is shown to be especially the most genuine, since it has been tested frequently by the plots of opposing thinkers; yet, the disposal of the lot being of God, the Catholic Church has maintained its own ascendancy, has reassumed its own power, and has led all the churches and the people to the reception of its own truth.
I have had to deliberate whether I ought to confine myself to the recital of events connected with the Church under the Roman government; but it seemed more advisable to include, as far as possible, the record of transactions relative to religion among the Persians and barbarians. Nor is it foreign to ecclesiastical history to introduce in this work an account of those who were the fathers and originators of what is denominated monachism, and of their immediate successors, whose celebrity is well known to us either by observation or report. For I would neither be considered ungracious towards them, nor willing to consign their virtue to oblivion, nor yet be thought ignorant of their history; but I would wish to leave behind me such a record of their manner of life that others, led by their example, might attain to a blessed and happy end. As the work proceeds, these subjects shall be noted as far as possible.
Invoking the help and propitiousness of God, I now proceed to the narration of events; the present history shall have its beginning from this point.
Source: Ecclesiastical History (New Advent)