A letter from Rupert, the abbot of Deutz, to Cuno, abbot of the monastery at Siegburg, about the reason why this work on John the evangelist has been attacked.

I have meditated by night in my heart and awakened, my father, O reverend and honourable Cuno, abbot of the monastery at Siegburg, and the result of my meditation and awakening was to write you. See how what I wrote has become like a lightening bolt for me: it keeps me from hiding and turns the differing attentions of various people toward me. On the one hand to those whose eyes are bleary from jealousy and are unaware of the salve of brotherly love everything is dark and hidden. But to those who have clear eyes out of good will (among whom, father, you are best disposed toward me), all the things that I write are crystal-clear and good, as I hear from you and from them. So my soul now sings for you and those like you as its reason and its justification what the holy church says of her sufferings: I am dark but comely, o daughters of Jerusalem, like the tents of Kedar, like the curtains of Solomon.

For what is darker, what more like the tents of Kedar, than that emptiness of presumption, by which they judge I have been so puffed up that I have rushed in to write? For since that voice of Christian law and instrument of catholic faith, Father Augustine, has spoken out on the gospel of John in a sonorous and sweet sermon-series, they imagine criticism and derogation of him from the fact that I have dared to consider that same gospel (the very word of God) after so great a teacher. They are extremely indignant, as if at an upstart, that I have dared to thrust myself among such ancient nobility or even to prefer myself out of a spirit of pride.

I however am confident that I have God as a witness in my soul that this is the reason which impelled me to do this, to deal with so high and so divine a gospel in my own words after such and so great a helper of catholic peace, namely that I was mindful of God and rejoiced in Him. For how I am judged or thought of by human opinion does not seem of any importance to me.

But those critics, whatever they may say, whatever they may offer as a proof, have no other reason than that some of them, at the same time that they wish the sacrament of the body and blood of the Lord to be only a sign for something holy, in accordance with the error of the late Berengar of Tours, even think that blessed Augustine agreed with this statement, which is completely false. I however contend that the sacrament is the true body of Christ which was offered for us and that it is his true blood which was shed for us, just as the catholic church holds. So they have tried to prove that I am disparaging blessed Augustine by deciding against him, whom Berengar had been accustomed to cite in defence of his error by twisting his words. But now almost no-one dares to profess or support this openly, since the whole catholic church knows that it is the true body and the true blood of Christ.

There is something else which they have cast up at me as strong proof of a crime, that I had dared to hesitate about the traitor Judas, whether he had been present at the sharing of that same sacrament, as the same Father Augustine claims, or had not been present but might be thought to have left already, as St Hilary firmly claims. This, o my father and o you daughters of Jerusalem, this is that great darkness by which I become dark in their eyes, says my soul, just as the tents of Kedar. They say that I am arrogant and unbelievably puffed-up, unable to leave any honest clerk alone ('clerk' is what they are accustomed to call any fairly well-educated man, of whatever order or way of life), unable to keep from accusing such a man of heresy. Undoubtedly this is what it is like to be, or be called, black as the tents of Kedar, a state of which it is written, 'His hand will be against all and the hand of all will be against him, and he will set up his tents far from the district of all his brothers.'

What am I to do, father? One man strove to take from me the truth of the body and blood of the Lord. Another found fault with me in a very hateful way because I will not say that the writings of our teachers are of a canonical authority equal to the Scriptures of the prophets and apostles. Still another taught that God wills evil, and that one and some others contended that Christ as a human being, a new person who was created according to the likeness of God and assumed into unity of person with God the Word, and who before his passion was inferior not only to God but even to his angels according to his humanity, did not in any way achieve equality with God. I have said enough about all such men in my apologetic works which I wrote before to students of religious knowledge and faith: you and they, o most worthy abbot, are witnesses and helpers that I have reported very accurately. What then shall I do, except to set up my tents far from them all and to consider their unprovoked hatred preferable to peace with them? Let them freely attack me and say that my tents are as black as those of Kedar! The truth, in whose clear voice my judgement rests, will overcome, so that my soul (just like Solomon's curtain, which he made out of the hides of dead animals) may be indeed comely, founded upon the faith and purpose of those who have been killed by violent persecution for justice's sake.

Now I set out briefly for you what and in what way I, while considering the life-giving sacrament of the body and blood of the Lord, explained the words of that same Lord in which he commends that sacrament, since this was the first of those reasons I have mentioned before. The sacrament is the body and blood of Christ in three kinds of essence but it differs in a fourth. For it is the body and blood of Christ in name, in reality, and in effect, but not in form.

It is the same in name, I say, because the high priest of heaven, who does not give empty names to things since he is Truth itself, assigned this name very emphatically. For he did not say merely 'Let this be called my body, let this be called my blood' but said 'This is my body, this is my blood.'

It is the same in reality, because it is truly the holy of holies, just as Jesus himself was the holy of holies in that form in which he was betrayed and pierced.

It is no less the same in effect, because just as Jesus, in that form in which he hung on the cross, has truly accomplished the remission of sins in all those who had lived in expectation of him from the creation of the world by faith or by the sacraments of faith of the Law, in every such person from the just man Abel to the thief whom he received for acknowledging him on the cross, so he, in those forms of bread and wine, truly accomplishes the same remission of sins in all those who have entered or are entering the same faith, now that that previous form has passed hence and withdrawn into heaven.

It is different in a fourth way, that is, in form, because that is most beneficial to us, not only so that the colour and taste of blood would not arouse disgust but also so that faith might have a valuable role to play, since human reason could not offer proof.