Arnoldus Saxo


Almost nothing is known about Albertus Saxo. The addition of "Saxo" to his name suggests he lived in Saxony. His dates of birth and death are unknown, though he most likely lived in the first part of the thirteenth century. He may have been a cleric. He also refers to himself with name Arnoldus Luca.


The works of Arnoldus other than De floribus rerum naturalium are not well known. He suggests in his prologue to that book that he had previously produced a book on the works of philosophers (Sermo de libris philosophorum), which appears to no longer exist. Other works attributed to him include a treatise on medicine (De causis morborum et figuris simplicibus quoque compositis medicinis), a treatise on vices and virtues, and a consolatio (Liber notabilium de consolatione Senecæ) [Draelants].

De floribus rerum naturalium

The De floribus rerum naturalium is an encyclopedia, albeit a short one, covering zoology, mineralogy, and astronomy, but the the zoological parts dominate, with chapters on quadrupeds, birds, fish and reptiles,.

Arnoldus used the Latin translation by Michel Scotus of Aristotle's De animalibus, which was published around 1220, so the De floribus rerum naturalium has to have been written after 1220 and probably in the 1230s.

The text of De floribus rerum naturalium is much shorter than that of other thirteenth century encyclopedias, which often fill 200 or more manuscript folios. Arnoldus's text, as found in the Erfurt manuscript, only requires 63 folios. While the text is organized in five parts (see below), the topics of each are not rigidly followed, with items that would logically appear in one appearing in another part, or in more than one. The entries for each animal are also brief, usually no more than a short paragraph, but the same animal often appears more than once, in descriptions of different properties. Overall, the text appears less structured and coherent than the other encyclopedias.

With the exception of Part 5 (De moralibus), Arnoldus generally follows Aristotle in describing the physical attributes of animals, without the moralizations and spiritual meanings found in the Bestiaries and in some other encyclopedias (e.g. the Etymologies of Isidore of Seville; the Liber de natura rerum of Thomas of Cantimpré).

Arnoldus's text was used by other encyclopedia authors, including Albertus Magnus, Bartholomaeus Anglicus and Vincent de Beauvais, though only Vincent actually cites him by name. He is also cited in the fifteenth century Hortus Sanitatis.

The five parts of the De floribus rerum naturalium and their chapters and articles, derived from the edition by Stange:

Capitula primi libri

  1. De celo et mundo
    On heaven and earth
  2. De essentia prime cause
    On the essence of the first cause
  3. De bonitate prime cause
    On the goodness of the first cause
  4. De probatione prime cause
    On the proof of the first cause
  5. De providentia prime cause
    Of providence in the first cause
  6. De ydea
    On the idea
  7. De yle
    On substance/matter
  8. De anima mundi
    Of the soul of the world
  9. De anima rationali
    On the rational soul
  10. De immortalitate anime
    On the immortality of the soul
  11. De quiete et penis anime
    On the quietness and penitence of the soul
  12. De natura celi
    On the nature of heaven
  13. De forma mundi
    On the form of the world
  14. De mundo archetipo
    On the archetypal world

Capitula secundi libri

  1. De natura stellarum
    On the nature of the stars
  2. De motibus astrorum
    On the motions of the stars
  3. De natura planetarum
    On the nature of the planets
  4. De motibus et iudiciis planetarum
    On the motions and judgment of the planets
  5. De saturno
    On Saturn
  6. De iove
    On Jupiter
  7. De marte
    On Mars
  8. De sole
    On the Sun
  9. De venere
    On Venus
  10. De mercurio
    On Mercury
  11. De luna
    On the moon
  12. De eclypsi solis et lune
    On eclipses of the sun and of the moon
  13. De ascensione lune
    On the ascension of the moon
  14. De effectibus ascensionis lune
    On the effects of the ascension of the moon
  15. De anno mundano
    On the world year
  16. De natura circulorum orbis
    On the nature of the circles of the world
  17. De stridore circulorum orbis
    On the sound of the circles of the world
  18. De qualitate et distantia circulorum orbis
    On the quality and distance of the circles of the world
  19. De quantitate terre
    On the quantity of land
  20. De centro et figura terre
    On the center and form of the earth

Capitula tertii libri

  1. De generatione elementorum
    On the generation of elements
  2. De natura elementorum
    On the nature of the elements
  3. De effectibus elementorum
    On the effects of the elements
  4. De generatione et corruptione simplicium
    On the generation and decay of simple things
  5. De generatione et corruptione compositorum
    On the generation and decay of compounds
  6. De generatione animalium
    On the generation of animals
  7. De generatione plantarum
    On the generation of plants
  8. De alimento et aucmento plantarum
    On the nourishment and growth of plants
  9. De perfectione et essentia plantarum
    On the perfection and essence of plants
  10. De accidentibus plantarum
    On the accident properties of plants
  11. De diversitatibus plantarum
    On the diversity of plants
  12. De effectibus plantarum
    On the effects of plants
  13. De causa putrefactionis omnium
    On the cause of the corruption and putrefaction of all things

Capitula quarti libri

  1. De galaxia
    On the galaxy
  2. De comete
    On comets
  3. De perpendiculari igne
    On the perpendicular fire
  4. De assub
    On the things below
  5. De rotunditate continente solem
    On the roundness of the sun
  6. De pluvia
    On rain
  7. De tonitruo et coruscatione
    On thunder and lightning
  8. De yride
    On rainbows
  9. De rore et nive
    On dew and snow
  10. De grandine
    On hail
  11. De ventis
    Of the wind
  12. De turbine
    On the whirlwind
  13. De terre motu
    On the movement of the earth [earthquakes]
  14. De mari
    On the sea
  15. De aquis fluminum
    On the waters of rivers
  16. De aquis calidis
    On warm waters
  17. De locis ardentibus
    On burning places

Capitula quinti libri

  1. De generatione montium
    On the generation of mountains
  2. De generatione lapidum
    On the generation of stones
  3. De generatione minerarum
    On the generation of minerals
  4. De argento vivo
    On mercury [quicksilver]
  5. De plumbo
    On lead
  6. De stagno
    On tin (?)
  7. De ere
    On "ere" (?)
  8. De ferro
    On iron
  9. De argento
    On silver
  10. De auro
    On gold
  11. De effectibus minerarum
    On the effects of minerals

Capitula sexti libri

  1. De natura generationis hominis
    On the nature of the generation of man
  2. De natura operationis hominis
    On the nature of the activity of man
  3. De natura generationis quadrupedum
    On the nature of the generation of quadrupeds
  4. De natura operationis quadrupedum
    On the nature of the activity of quadrupeds
  5. De natura generationis avium
    On the nature of the generation of birds
  6. De natura operationis avium
    On the nature of the activity of birds
  7. De natura generationis piscium
    On the nature of the generation of fishes
  8. De natura operationis piscium
    On the nature of the activity of fish
  9. De natura generationis reptilium
    On the nature of the generation of reptiles
  10. De natura operationis reptilium
    On the nature of the activity of reptiles

Short descriptions of 80 stones

  1. De homine
    On man
  2. De animalibus rapacibus
    Of predatory animals
  3. De domesticis et eorum membris
    On the domestic animals and their members
  4. De avibus
    On birds
  5. De piscibus
    On fish
  6. De reptilibus
    On reptiles
  7. De plantis
    On plants
  8. De lapidibus
    On stones and gems
  9. De speculis
    On mirrors
  10. De visu
    On vision

Capitula primi libri

  1. De virtutis diffinitione
    On the definition of virtue
  2. De virtutis divisione
    On the divisions of virtue
  3. De virtute intellectuali et consuetudinali
    On intellectual and customary virtue
  4. De beatitudine
    On bliss
  5. De temporis observantia
    On the observance of time
  6. De loci constantia
    On the constancy of place
  7. De vite perseverantia
    On the persistence of life
  8. De mortis presentia
    On the presence of death
  9. De eternitatis custodia
    On the guard of eternity

Capitula secundi libri

  1. De prudentia
    On prudence
  2. De doctrina
    On doctrine
  3. De disciplina
    On discipline
  4. De conversatione
    On conversation
  5. De iustitia
    On justice
  6. De iudicio
    On judgment
  7. De conscientia
    On conscience
  8. De religione
    On religion
  9. De amicitia
    On friendship

Capilula tertii libri

  1. De fortitudine
    On fortitude
  2. De divitiis
    On riches
  3. De paupertate
    On poverty
  4. De patientia adversitatis
    On patience in adversity
  5. De adversitate mortis
    On the adversity of death
  6. De temperantia
    On temperance
  7. De misericordia
    On mercy
  8. De clementia
    On clemency
  9. De beneficiis
    On kindness/service

Capitula quarti libri

  1. De dignitatibus
    On dignity
  2. De improbanda felicitate presenti
    On the improbable present happiness
  3. De felicitatis inconstantia
    On the inconstancy of happiness
  4. De ambitione
    On ambition
  5. De adulatione
    On flattery
  6. De voluptate
    On voluptuousness
  7. De crudelitate
    On cruelty
  8. De discordia
    On discord
  9. De stultitia
    On stupidity

Capitula quinti libri

  1. De superbia sive de inani gloria
    On pride or vainglory
  2. De ira
    On anger
  3. De invidia
    On envy
  4. De desidia sive de accidia
    On apathy or sloth
  5. De avaritia
    On avarice
  6. De gula sive de castrimargia
    On gluttony or over-eating
  7. De luxuria
    On luxury
  8. De diversitate delictia
    On the diversity of delight
  9. De malitia incorrigibili
    On incorrigible malice


Arnoldus refers to various books of mostly ancient writers. Several of the works of Greek and Arabic authors had been translated into Latin by the time Arnoldus wrote his book, so he could have read any or all of the texts in this list, either directly or via the works of his contemporaries.

  • Aristotle: De anima (On the soul), De animalibus (On animals), De proprietatibus elementorum (On the properties of elements [attributed]), De somno et vigilia (On sleep and sleeplessness), De vegetabilium (On plants [attributed]), Meteorologica (Meteorology)
  • Alchyldis (unknown): De venenis (On poisons)
  • al-Ghazali (Arab philosopher,11th-12th century): De sensu et sensato (On sense and the sensible)
  • Avicenna (Arab philosopher, 10th-11th century): Libro medicinali (Book of medicine)
  • Belbetus (unknown): De sensibus (On the senses)
  • Constantinus Africanus (11th century translator of Arabic texts): De coitu (On sex), Libro viaticum (a book on medicine, actually by Ahmed Ibn Al Jazzar)
  • Aesculapius: De membris (On the limbs)
  • Galen [Galenus] (Greek physician and philosopher, 1st-2nd century): De spermate (On sperm), De complexionibus (On the complexions)
  • Isaac Judaeus [Isaac Israeli ben Solomon] (9th century Jewish physician): De dietis particularibus (On diet in particular), De dietis universalibus (On diet in general)
  • Jorach [Iorach] (unknown Jewish author whose text is lost): De animalibus (On animals)
  • Pythagoras: Libro Romanorum (Book of the Romans)
  • Serapion the Younger (12th century Arabic physician): De simplici medicina (On simple medicaments)
  • Zeno [Zenon, Pseudo-Zeno] (probably not the philosopher Zeno): De naturalibus (On nature)

For more on Arnoldus's sources, see Draelants, 2000.


There are about 15 manuscripts containing parts of the De floribus rerum naturalium, but very few existing manuscripts that include the entire text. The most complete is the one used by Stange for his edition, Universitätsbibliothek Erfurt, O. 77. A possibly abbreviated copy is found in Bodleian Library, MS. Lat. e. 34. Extracts from the text are included in a few manuscripts, especially from Part 5, De moralibus. Part 3, the lapidary, appears on its own in several manuscripts, for example Bibliothèque Nationale de France, lat. 7475.


Unlike the other thirteenth century encyclopedias, the De floribus rerum naturalium does not have a section where each animal is described individually. Instead, multiple animals are dealt with in each of the animal-related chapters of Parts 2 and 4. Each animal has only a brief entry, never more than a few sentences. There is no real structure to the animal descriptions; some animals have repeated mentions. The animals are not always confined to the appropriate sections, with some quadrupeds appearing in chapters on birds or fish and birds appearing in quadruped chapters, as well as in their own sections. Some animals are covered in two or more locations in a chapter, as though Arnoldus simply wrote down the accounts as he thought of them.

This lack of organization makes a list of animals as they appear in the text meaningless, so the following list is in alphabetical order.