Paraphrased excerpts from the Latin De rerum naturis text, based on the transcriptions by Schipper and Migne.

Prologue 1

To the most excellent lord, and worthy of all honor, to the king Hludouicus [Louis]. Rhabanus, the humblest of God's servants, prays for eternal happiness in Christ.

I have heard of your good opinion which is preached throughout all the provinces of Germany and Gaul, and almost in all parts of Europe they sing their praises with great exultation, and I implore the Lord's mercy to grant that this may come to a healthy end with good growth. Because of this, my labors were expended as much as I could in expounding the sacred scriptures by the generous grace of the servant of Christ himself. I did not wish to have it without your communion, but I directed to your veneration certain treatises and commentaries written in divine books. Lately also, when I was found in your presence, I told you that I had completed a little work on the propriety of speech; and with the mystical significance of the things which you have requested to be directed to you even from my parochialism, I have gladly done what you asked, and have sent the work itself to you, completed in twenty two books, so that if it pleases your serenity you may read it. And if anything worthy of correction has been found in it, you and your most sagacious readers will take care to correct it as reason dictates. For in it there are several expositions of the nature of things, and of the properties of words, as well as also of the mystical meaning of things, which is why I thought it should be arranged in such a way, that the prudent reader may find, in a continuous manner, the historical and mystical interpretation of things. And thus he could find enough in this way to satisfy his desire to learn the manifestation of both history and allegory. Wherefore it seemed to me better to take the beginning of this work from our founder himself, who is the head and beginning of all things, because he naturally subsists everywhere, is either the author and creator of all things, or a creature founded by him. For from Him and through Him and in Him are all things that made heaven and earth, the sea, and all that is in them. So, therefore, first from the most good and true founder of ours, this is the father and the son and the holy spirit. Of the one and only almighty God, according to the smallness of my talent, I argued as much as the divine grace allowed me to write something. Afterward I set out to have a discussion about celestial and terrestrial creatures, not only about nature but also about life and their effects, so that the diligent reader may find in this work and nature a property according to history and a spiritual meaning according to a mystical sense placed at the same time. And because it did not suit me to keep silent about the holy men who are mentioned in the Old and New Testaments and their mystical activities, as well as about the places where they lived, I decided to translate their names and the places from the Hebrew language into Latin. In order that I might therefore explain the mystical meaning more easily, I have also added in the present work not a few things about the Catholic faith and the Christian religion, and on the contrary about the superstition of the Gentiles and the error of heretics, about philosophers and more, and about false gods, about the languages of the nations, about kings and of soldiers, and of all the names and affinities of man and his parts, and of the rest of living things, of stones, trees, and grasses that grow in the earth, of various arts and crafts, and many other things, all of which it would be too long to enumerate in the prologue. Moreover, I took care to enumerate them more completely in the chapters of the individual books. I determined that this whole work, as I have said above, should be dispersed into twenty-two books, under which number the blessed Hieronymus, the interpreter of the divine law, asserted that he had compiled the old testament of the divine law, from the interpretation and exposition of which I have brought to light certain obscure things in this work.

De pecoribus et iumentis (Book 7, chapter 8)

Adam gave the first names to all living creatures, each one according to its nature. And the nations gave names to each of them from their own language, but Adam did not put those names in the Latin and Greek tongues or any of the languages of the barbarian nations, but in that language which was known by all before the flood, which was called Hebrew. But animals, or living things, are said to be animated by life and moved by spirit. According to allegory, animals represent brute men, thinking only of earthly things, whence it is said, animal man does not perceive the things which are of the spirit of God, for it is foolishness to him. From here and through the psalmist it is said: Your animals will dwell in it. When the nations were empty of true religion they were animals, until they came to the master with whose help they became rich. Now they need nothing, but to be filled with reason and full light, and they will dwell in the church, when they have truly perceived the worship of religion in the most merciful way. Likewise, as the Apostle says: The body is animal but it is also spiritual, and not first spiritual, but that which is animal. Whence the spiritual in the animal body signifies the state of the present life which a man wears a mortal body for a long time. But the spiritual body signifies the immortality of the future life, when this corruptible body is clothed with corruption. It is an animal body, so long as it is supported by food in order to live. But the spirit, having returned to life, will need nothing of these, and all the aforesaid are closed in this sense, for nothing else is contained in the above, except that the animal body dies, and the spiritual rises again, and it neither eats anymore, nor is it weak, nor is it foul, nor is it sick by nature, because animal from Adam, but spiritual through Christ and the resurrection of the dead. The animals that chew the cud, which are described in the pure law, are the holy men, always meditating on the divine precepts with their mouth and heart and their work, as it is in the Psalm: The meditation of my heart is always before thee. Indeed, the animals that do not chew the cud are the sinners in the world who do not pay attention to the law of God and do not study it in meditation. For the animals that split the hoof and chew the cud, which are described in the pure law, are faithful believers in both testaments, and as it were in two hoofs the foot of the work, fixing the shape of the course. For the animals which chew the cud, and do not split the hoof, which are spoken of as unclean, are the Jews, who meditate on the old testament with their mouths, but by no means receive the new.

Likewise, the flesh of the horned animals which are ordered to be offered in sacrifice of God, is granted as the food of the faithful, such as goats, rams, stags, does, and roe deer. Horns signify the holy virtues, resisting the devil and bearing the guilt of sinners. The horn mystically signifies Christ's kingdom in the gospel, and he raised up the horn of salvation for us in the house of his son David. Horns have authority over all time. Whence in the Apocalypse: I saw a lamb as if it had been slain, having seven horns and living eyes. The horn as the mark of the cross of Christ in Habakkuk: the horn in his hands where his strength is hidden. The horned pride of the devil, or his power in the present time, or the kingdom of the Antichrist. In the Apocalypse: Horned kingdoms of this age. In Daniel: Horned pride. In the Psalm: And from the horns of unicorns my humility. And elsewhere: I will break all the horns of sinners. Quadrupeds are so called because they walk on four feet, but some of which, while they are like cattle, are not under human care, such as stags, does, and onagers, and the rest. But there are no wild beasts like lions nor wild cattle that can be useful to men. We call cattle everything that lacks human language and image, but properly the name of cattle is usually applied to those animals which are either suitable for grazing, such as ewes and pigs, or suitable for human use, such as horses and oxen. But there is a difference between cattle and livestock. For the ancients commonly used to call all animals cattle. But you shall eat cattle only those animals which are produced as cattle. In general, however, every animal is called cattle from grazing. Thence they derived the names of the beasts, because they lighten our labor or burden by their help in pulling or plowing. For the ox pulls the plow and turns the hardest clods of earth. The horse and the donkey carry the burdens and ease the labor of men in marching. Whence also cattle are called from the fact that they help men, for they are animals of great strength. But the mystical animals are faithful in the church but lack spiritual understanding.

De bestiis (Book 8, chapter 1)

The name "beast" is properly applied to lions, leopards, tigers, wolves, and foxes, and dogs, and apes, and other things which eat either with their mouths or claws, excepting the beasts called snakes, which eat birds. In general they use their natural freedom and are driven by their own desires. For their pleasures are free, and they wander hither and thither, and are directed wherever the mind leads them.