Having with difficulty obtained a little leisure, I have been able to recover from bodily fatigue on my return from Armenia, and to collect the sheets of my reply to Eunomius which was suggested by your wise advice; so that my work is now arranged in a complete treatise, which can be read between covers. However, I have not written against both his pamphlets  ; even the leisure for that was not granted; for the person who lent me the heretical volume most uncourteously sent for it again, and allowed me no time either to write it out or to study it. In the short space of seventeen days it was impossible to be prepared to answer both his attacks.
Owing to its somehow having become notorious that we had laboured to answer this blasphemous manifesto, many persons possessing some zeal for the Truth have importuned me about it: but I have thought it right to prefer you in your wisdom before them all, to advise me whether to consign this work to the public, or to take some other course. The reason why I hesitate is this. When our saintly Basil fell asleep, and I received the legacy of Eunomius' controversy, when my heart was hot within me with bereavement, and, besides this deep sorrow for the common loss of the church, Eunomius had not confined himself to the various topics which might pass as a defence of his views, but had spent the chief part of his energy in laboriously-written abuse of our father in God. I was exasperated with this, and there were passages where the flame of my heart-felt indignation burst out against this writer. The public have pardoned us for much else, because we have been apt in showing patience in meeting lawless attacks, and as far as possible have practised that restraint in feeling which the saint has taught us; but I had fears lest from what we have now written against this opponent the reader should get the idea that we were very raw controversialists, who lost our temper directly at insolent abuse. Perhaps, however, this suspicion about us will be disarmed by remembering that this display of anger is not on our own behalf, but because of insults levelled against our father in God; and that it is a case in which mildness would be more unpardonable than anger.
If, then, the first part of my treatise should seem somewhat outside the controversy, the following explanation of it will, I think, be accepted by a reader who can judge fairly. It was not right to leave undefended the reputation of our noble saint, mangled as it was by the opponent's blasphemies, any more than it was convenient to let this battle in his behalf be spread diffusely along the whole thread of the discussion; besides, if any one reflects, these pages do really form part of the controversy. Our adversary's treatise has two separate arms, viz. to abuse us and to controvert sound doctrine; and therefore ours too must show a double front. But for the sake of clearness, and in order that the thread of the discussion upon matters of the Faith should not be cut by parentheses, consisting of answers to their personal abuse, we have separated our work into two parts, and devoted ourselves in the first to refute these charges: and then we have grappled as best we might with that which they have advanced against the Faith. Our treatise also contains, in addition to a refutation of their heretical views, a dogmatic exposition of our own teaching; for it would be a most shameful want of spirit, when our foes make no concealment of their blasphemy, not to be bold in our statement of the Truth.
 both his pamphlets. The sheets' which Gregory says that he has collected are the 12 Books that follow. They are written in reply to Eunomius' pamphlet, Apologia Apologiæ,' itself a reply to Basil's Refutation. The other pamphlet of Eunomius seems to have come out during the composition of Gregory's 12 Books: and was afterwards answered by the latter in a second 12th Book, but not now, because of the shortness of the time in which he had a copy of the heretical volume' in his hands. The two last books of the five which go under the title of Basil's Refutation are considered on good grounds to have been Gregory's, and to have formed that short reply to Eunomius which he read, at the Council of Constantinople, to Gregory of Nazianzen and Jerome (d. vir. illust. c. 128). Then he worked upon this longer reply. Thus there were in all three works of Gregory corresponding to the three attacks of Eunomius upon the Trinity.