I am pleased to hear you express yourself so boldly in behalf of evangelical truths, and that you have so far unfolded them by argument. But I would fain know how, and from what cause it was, that this heresy took its rise, even supposing it to have been introduced by Satan and his followers into the church.
I should be worse than an infidel were I not to defend unto the death the law of Christ; and certain I am, that all the heretics and disciples of Antichrist can never impugn this evangelic doctrine. On the contrary, I trust, through our Lord’s mercy, to be superabundantly rewarded by him after this short and miserable life for this lawful contention which I wage. I know from the Gospel, that Antichrist, with all his devices, can only kill the body, but Christ, in whose cause I contend, can cast both soul and body into hell-fire. Certain I am, that he will not suffer his servants to be destitute of what is needful, since he freely exposed himself to a dreadful death, and has ordained that all his more beloved disciples shall undergo severe suffering with a view to their profiting.
The reason why men fall into this heresy, is that they disbelieve the Gospel, and embrace in preference the papal laws and apocryphal sayings. And of all the kinds of infidelity that ever grew up in the church of God, this draws men down deeper and more imperceptibly into the vortices of error, and causes more to apostatise from our Lord Jesus Christ. And be it granted that Innocent III. was led away by this madness, though the friars take upon themselves to say that it is not my place to  discuss this point, yet I am sure from the faith of Christ, that whatever he (Innocent III.) has laid down in this matter, should not be received by believers, except in as far as it is founded on the commandments of the Gospel, for the same faith of Christ makes me confident that all truth is contained therein, and especially all truth relating to faith, and most in harmony with its design. Since these things are not from Christ or his law, but, on the contrary, it is contained in his law, as is plain from what is said before, that this sacrament is the body of Christ and bread, every believer ought accordingly to obey his Lord herein. But herein it is manifestly inferred, that the sacrament is not an accident without a subject, since it cannot be shown that God has raised an accident to be his body. Accordingly, adhering to the faith, I will deny this as the greatest heresy, and with this view I have elsewhere sent the satraps the following conclusions thereupon, with a protest agreeably thereto. The first is:—If by virtue of these sacramental words an accident is matter without a subject in the sacrament of the altar, that accident is itself the sacrament. It is plain from this that the said sacrament, according to the concurrent acknowledgment of these heretics, is not a substance, so that the sacramental words leave nothing remaining in the sacrament save this sort of accident. The second conclusion is, that—Of all the heresies that have ever grown up in the holy church of God, none is more abominable than that which makes this venerable sacrament an accident without a subject:—it being plain, that by this heresy, the very words of Christ are made to be heretical, so far as in it lies, and heresy is introduced over the greater part of the church. The third conclusion is, that this sacrament is, on the testimony of the Gospel, true bread naturally, and the body of Christ veritably and sacramentally, as the above-mentioned passages from the Gospels show.
With regard to your second question, it appears to me that Christ, who is head over all devils, teaches us figuratively by this, how the kingdom of the evil one is divided against itself, and must finally be made desolate, showing that its principal supporters in their very blessing are divided against themselves—as in the matter of the sect of the friars, so that each one of them is opposed to all the rest, and no one can efficiently maintain its own sentiments. And inasmuch as their prelates presume to bless, for the payment of money, those whom the Lord hath cursed, so they often curse those whom the Lord hath blessed; accordingly the Lord signifies to us, in that passage of Malachi, that their benediction after their own pleasure, should often be called the malediction of God. For they say that in the consecration of their host, they bless the bread and wine so that it becomes nothing, since according to their doctrine no part of it remains in the body of Christ, or in his sacrament, but taking annihilation in its proper sense, it is annihilated and turned into nothing. But Christ, though he was called an austere man by the slothful servant, never cursed anything whatever with a severity like this, for when he cursed the fig-tree (Mark 11.) the substance of the tree remained, since Christ destroyeth not utterly his creatures on account of sin, or the appearance of sin, and since no creature can do anything unless without the previous act of God. Hence it is plain, that though they may bless the bread (as they falsely say) so as to cause it to become nothing, yet Christ, since it is his own workmanship, preserves it. Nor must we pass over what is said by John, in his treatise “On God,” that the bread remains bread, but that where it is unknown, since believers are well assured that the bread, by virtue of the blessing of Christ, is turned into a something better, because it is turned into the body of our Lord, and remains bread because the body itself remains sacramentally; and if they say it is transubstantiated, by virtue of the sacramental words, it is enough for me, since that substance cannot pass into another which has no existence in the passage. Let us praise Jesus Christ, then, in that the author of this lie is not He who spake and it was done, but rather that liar who spake and it was not done, who commanded and it was brought to nought. But if you reply that it follows from this, that the pope and his cardinals have many times erred from the faith, and often deceive both themselves and their churches, the conclusion is true, though lamentable. Whether, however, they died penitent for such heresy, or remained heretics after death, it is not for us rashly to decide. Yet God who knoweth things secret knoweth the truth in this matter, as do those to whom it is his pleasure himself to reveal it. For we are not bound to proclaim or believe that any pope, as such, is a father in the greatest blessedness after death, as his greedy flatterers during his lifetime clamorously assert, but the more he departed in life, even to the last, from the pattern of Christ, the more deep will be his condemnation in hell. But I believe many have been led into this heresy who finally repented, as was the case, in my opinion, with the Bishop of Lincoln and others, who have left behind them in their writings the opinion, that an accident cannot exist without its subject, and yet the aforesaid Bishop of Lincoln, in his “Glossa de Divinis Nominibus,” thus writes—“An accident may perhaps (forte) exist without a subject.” I believe this subtle doctor to have meant that such an accident in the sacrament must exist in the act of our mind, since we have sensation actually to admonish us. But the consideration of the quiddity of its substance must be put in abeyance, and our consideration of the created substance must be employed about that which is signified by it—as a man entering a church does not set himself to consider the quiddity of the wood of the image, or the cross, but worshippeth it in respect of that of which it is the sign. So it is in the matter of the consecrated host; and because this is sometimes the case and sometimes not, I repeat what the Bishop of Lincoln says, “there may perhaps be an accident without a subject.” It is in this way that those philosophers speak, who hold that time has its existence in the mind, and that it is rendered sensible by the act of attention. For the existence of time is known to us because it is the measure of sensible motion, by the actual consideration of the mind; just as that which is perceptible to the senses, has this passive power reduced to act, during the time that it is actually being perceived. I think it very probable that great philosophers have been secretly of this opinion on the matter. But it would be useless to inquire into the intention of the author of this error. So I leave the discussion and contention with regard to this gloss to be carried on by theologians, being certain always of the faith of the Gospel, whereupon I rest without the smallest fear.