Pliny the Elder [1st century CE] (Natural History, Book 8, 68): The services of the ass kind are undoubtedly bountiful in ploughing as well, but especially in breeding mules. ... The ass itself is very bad at enduring cold, and consequently is not bred in the Black Sea district; and it is not allowed to breed at the spring equinox like all other cattle, but at midsummer. The males make worse sires when not in work. The females breed at two and a half years old at earliest, but regularly from three; they can breed as many times as mares, and in the same months and in a similar way. But the womb cannot retain the genital fluid but discharges it, unless the animal is whipped into a gallop after coupling. It seldom bears twins. When about to bear a foal it shuns the sunlight and seeks the shadow, so as not to be seen by a human being. It breeds through all its lifetime, which is thirty years. It has a very great affection for its young, but a greater dislike for water: she-asses will go through fire to their foals, but yet if the smallest stream intervenes they are afraid of merely wetting their hooves. Those kept in pastures will only drink at springs they are used to, and where they can get to drink by a dry track; and they will not go across bridges with interstices in their structure allowing the gleam of the river to be seen through them; and, surprising to say, they may be thirsty and have to be forced or coaxed to drink, if the stream is not the one they are used to. Only a wide allowance of stall-room is safe for them to lie down in, for when asleep they have a variety of dreams and frequently let out with their hooves, which at once causes lameness by hitting timber that is too hard unless they have plenty of room to kick in. The profit made out of she-asses surpasses the richest spoils of war. It is known that in Celtiberia their foals have made 400,000 sesterces per dam, especially when mules are bred. They say that in she-asses the hair of the ears and the eyelids is an important point, for although the rest of the dam's body is all one color, the foal reproduces all the colors that were in those places. Maecenas set the fashion of eating donkey foals at 598 banquets, and they were much preferred to wild asses at that period; but after his time the ass lost favor as a delicacy. Animals of this genus very quickly flag when their sight begins to go. - [Rackham translation]

Saint Ambrose [4th century CE] (Hexameron, Book 6, chapter 3.11): The donkey is a slothful and stupid animal, an easy prey to all mischance. - [Savage translation, 1961]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 1:38): The ass (asinus) and the small ass (asellus) are so called from sitting (sedere), as if the word were asedus. The ass took this name, which is better suited to horses, because before people captured horses, they began by domesticating the ass. Indeed, it is a slow animal and balks for no reason; it allowed itself to be domesticated as soon as mankind wished it. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Quadrupeds 4.2): As the Liber rerum says, the ass is a deformed animal, vile and contemptible, with a large head, broad and long ears beyond the cubit length, a thin body, not knowing how to be affected. On its shoulders it bears the stigmata of the cross, and this with merit, because Christ hastening to his passion to redeem the world by death, sat behind him lowly, poor and meek. The ass, then, is an animal ignorant of discord, a friend of peace, meek, patient in spite of the hardest blows, burdened and not rebelling against burdens, even beyond what it can bear. They are good by nature. The vices are these: the ass is a lustful animal, stronger and more powerful in the hindquarters than in the forequarters (for it carries the burden in the hindquarters), sluggish in walking and slow, brutish and unreasonable beyond all living things, while walking on the road it does not know how to give way to those who come across it, and it has a horrible braying. Young asses have some beauty in their youth, but the older they get, the more ugly they become. An ass copulates after thirty months, but does not give birth until after three years. Now, as Pliny says, the milk of an ass is the whitest, and is supposed to contribute to the whiteness of the skin. Hence we find that Poppea, Nero's wife, bathed herself in the milk of an ass. As the Experimentator says, asses are for the most part weak, having rheumatism on one side; if it flows internally from the nose and flows over the lungs, it dies. Eating the flesh of asses generates the worst blood and is difficult to digest; but they are finer than the flesh of horses. As the Liber Kyrannidarum says, if you make a ring from the hoofs of an ass and give it to one possessed by a demon to carry, he will be freed the same day. If its tears are mixed with oil and put into a lamp and lit, all at the feast will see that they have the heads of asses. The ass eats thorns with pleasure. Hot ass's milk strengthens the teeth and soothes their pain (especially if they have been rubbed with it). It also removes sighs. If you remove the ass which is placed beside her child, and want the child to follow, the child will remain in the place where the mother had left it, and will not move another step for five paces, but will wait for the mother in the place where she had left it. Now the ass is a very cold animal, and for this reason they are not born in cold places, since its nature cannot suffer too much cold, especially at the time of conception. Hence in the region called Scotland, and in its relatives and in similar regions, as in Pontus, an ass neither conceives nor begets an ass. For this reason asses do not come together at the equinox, the time when horses come together, but in the summer, so that the birth and generation of offspring takes place in the hot season. And they bear in the womb for a whole year. In the land of the North, which is the coldest of all habitable lands, asses are not found in extreme cold, because they cannot live there. As Pliny says, the bones of asses are more beautiful than other bones. A ass rarely gives birth to twins. In childbirth it flees from the light and cries out for darkness, so that it may not be seen by man. It gives birth all its life, which ends at the age of thirty. O truly blessed, whose life persevering without complaint of crime, the fruits of good works have been accomplished in innocence: for he who perseveres to the end will be saved. Through the fires they tend to the children: No one has greater love than to lay down one's life for one's friends. And in this the laziness of the prelates is pointed out, who do not want to endure even the slightest tribulation for their subjects and in this prove themselves mercenaries. If there is a stream, asses are afraid to touch it with their feet at all. Some may drink only from the usual fountains, and only from the best. - [Badke translation/paraphrase]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book18.8): The Asse is called Asinus, and hath that name of Sedendo, sitting, as it were a beast to sit upon. For men sate & rode uppon Asses before that they used horse to ride upon, as Isidore saith, libro 17. And is a simple beast and a slow, and therfore soone overcome & subject to mans service. Or else this name Asinus commeth of A, that is not having, & Synos, yt is wit, as it were a beast without wit. And of Asinus commeth Asellus, that is a lyttle young Asse, that is fayre of shape and of disposition while he is young and tender, before he passe into age. For the elder the Asse is, the fouler he waxeth from day to daye, and hairie and rough, and is a melancholyke beast that is cold and drye, and is therefore kindlye heavie and slow, and unlustie, dull and witlesse, and forgetfull: Neverthelesse he beareth burdens, and may away with travaile & thraldome, & useth vile meat and little, & gathereth his meate among Briers and thornes, and thistles. And therefore Avicen[na] saith, libro. 8. and Aristotle sayeth also, small birds that nestleth them in bushes, thornes, and briers, hate the asse. And therefore small Sparrowes fighteth with the Asse, for the Asse eateth the thornes, in the which ye Sparowes make theyr neasts. And also the Asse rubbeth and froieth his flesh against the thorns, and so the birds or the egges of the Sparowes falleth out of ye neast down to the ground. And when that the Asse reareth & heaveth up her head, then by a strong blast the thornes mooveth & shaketh, and of the great noyse the birdes he afearde full sore, and falleth out of the neast. And therfore the bréed birds suffereth them to leap on the face of the Asse, & bite & smite and réese to his eyen with their billes. And if the Asse have a wouude or a scab in the ridge or in the side, of pricking of thornes, or in any other wise, the Sparows leapeth on the Asse & pecketh with their bills in the wounds or in the sores, for the Asse should passe fro their neasts. And though such a Sparow be full lyttle, yet unneth may the Asse defend himselfe against his réese, pricking, and biting. Aristotle sayeth, and so doth Avice[na] also, that she ranen hateth full much the asse, therefore the raven flyeth above the asse, & laboureth with his bill to peck out his eyen: but the déepnes of eien helpeth the asse, and thicknes and hardnes of the skin, for therewith the asse closeth her eyen, and healeth her sight, and defendeth against the réesing and pricking of Foules: also his long eares and mooving thereof helpeth, for therewith hée fearesh smal birds, that réese to peck out his eyen: also libro. 8. Aristotle sayeth, that the Beare fighteth with the asse and with the Bull, because he eateth rawe flesh, & this is the cause why he fighteth with them, for he desireth to eate of their flesh. Libro. 18. cap. vit. Plinius speaketh of the Asse & sayth, that the smoak of the Asses hoofe helpeth the birth of a childe, insomuch that it bringeth out a dead childe, and shall not otherwise be layde to, for it slayeth a quicke childe if it bée oft layde to, and lyeth too long time. And new dirt of the same beast stauncheth bloud wonderfullye. And his lyver holpeth against the falling evill of children. Libro. 28. cap. 10. Plinius sayeth, that the Asses milke and Asses bloud helpeth against the biting of a Scorpion. And men saye, yt if a man looketh in an Asses eare when he is smit with a Scorpion, anone the mallice passeth. Also all venimous thinges flieth smoake of the Asses liver. Also in eodem cap. 9. it is said, that the Asses milk helpeth against venimous plaister, and against the mallice of Seruse or of quicke silver. Also li. 9. Assess bones brused & stamped, and sad, helpeth agaynst venimme, if the broath therof be dronken: and urine of the Male asse with Nardus kéepeth & saveth and maketh much haire. Libro 8. cap. 44. Plinius sayeth, that the Asse is a beast that maye worst awaye with colde, and bréedeth not therefore in colde Countryes and lands, and so he bréedeth not in Pontus: and therefore Ari[stotle] saith, though the asse be full colde and dry, yet he is ful lecherous, but he is not moved to gendring ere he be .30. moneths olde: and though be due then the worke of gendering, yet he gendereth no broode ere hee be full thrée yéere olde: and so Plinius sayth there, that the birth of the asse is most in idlenesse after 30. moneths, and is lawfull & profitable after thrée yeare. Also Aristotle saith the same, li. 5. & Plinius saith thereto, that the asse foaleth selde two coltes. When the female shall foale, she flyeth light, and séeketh a darke place that she be not seene, and loveth her foale so much, that she passeth through a fire to come to her foale: and ye asse breadeth full sore to passe over water, & scrapeth therein: and when she is compelled, & must needes passe over a water or river, and wadeth therein, then she pisseth therein: and the asse passeth not gladlye, where he may sée the water through the plankes, for he hath a féeble braine, and is soone grudged, and dreadeth therefore and falleth through the chinnes of the bridge into the water, that he séeth running there under: and the asse drinketh not gladly but of small wells that he is used to, and those that he may come drie footed to: and wonder it is to tell, yt though an asse be sore a thirst, if his water bée changed, unneth he drinketh thereof, but if it be like the water that he is wont to drinke of. Plinius. li. 28. cap. 7. sayth, that if the female asse eateth Barlye wet in menstruall bloud, as manye graines as shée eateth, so wet, so many yeres afterward shall she not conceive. The Mule is gendered betwéene an asse and a Mare: but to such gendering are Mares chosen, that passe in age foure yeare, and not ten yeare, and gender not alwaye either with other: Of this beast is two manner of kind: the one is gendered betwéene an horse and an asse, and that other betwéene an asse and a Mare. But the one kinde withdraweth him from ye other, but if they be fed together in youth with one manner milke. Therefore it is said, that heardes that desire to have Mules and burdones gendered of divers kindes of beasts, use this crafte, to bring forth young coltes of Mares, and set them in darkenesse to teates of asses, and to féede them with asses milke, and such horse colts when they be of age, bée mooved in time of gendering to gender with asses: also lykewise asses coltes be set to sucke teates of Mares, and be fed with Mares milke, and such colts gender with Mares when they be of age: and so of such gendering betwéene an asse and a Mare commeth a beast that was called Ninnulus in olde time, but we call a beast so gendered Burdus, and call such beasts gendered betwéene an asse and a Mare, a Mule: and libro. 15. Aristotle sayeth, that if an asse gendereth with a Mare that is full fat, the conception of the Mare is corrupted, for coldnesse of the semen of the asse. For the Semen of the Asse is most cold by kinde, and the matter of them, and the matter of the Mare is hot, & therfore when the hot is meddeled with the colde, then the meddeling is tempered, then therof may come conception, and the colt may be saved yt is gendered betwéene an horse and a female asse: and also likewise the colt yt is gendered betwéene an horse, and a Mare: but the hée of the Asse and of the Mare, that is the Mule, gendereth not, because of colde and naturall complection of both horse and Asse, that hath mastrye in the Mule. And therefore the mule gendereth not another beast, as hée saith. Also there he saith, yt if an asse gendereth with the same asse afterwarde, hee maketh her cast her colt, & the cause therof is, as Avicen[na] saith, for coldnesse of the semen of the asse cometh, & corrupteth & destroyeth temperatnesse of the first Semen, for the Semen of the asse is cold in complection, & brought to temperatnesse, by kind heat of ye male horse: & so when the semen of the female asse yt is colde by kind, or by complection, with coldnes of ye kinde with female by strength therof, the first temperatnesse commeth of ye hot semen of the horse, & of the colde semen of the asse, & this is the cause why every female mule is barren, as Avicen[na] saith: for the male asse yt is the father of the Mule, is passing cold of complection, and in the Mare that is mother, yt is hot, because of the heat of the horses kind. And therfore though the heat of the semen of the mother, that is the Mare, tempereth the cold semen of the asse, so that a beast may bée gendered, yet in the beast yt is gendered, the coldnesse of the father and mother abideth and hath mastry therein, and disposeth kindly to barrennesse. And there is a manner. Asse, that is called Indicus Asinus, and hath an horne in the middle of ye forehead, and is whole footed on all foure. For everye beast that hath two hornes is clove footed: and therefore this asse Indicus hath but an horne, for he is not clove footed, as Aristotle saith, lib. 2. But not everye cloave footed beast hath hornes, but againeward, if he be horned, he is clove footed, as it fareth in the Bul, and in the sheepe, Hart, and other such, as Aristotle sayth there. Libro. 7. Aristotle sayth, that the Asse, Mule, and horse, eateth fruit, hearbes, and grasse, and be fatted with water, and love more thick water then cléere. And the cow again loveth better cléere water then thicke. Also lib. codem, Aristotle sayth, that for the more part Asses waxe sick in one manner of sicknesse that is called Milide, and this sicknesse is first in the head, and then hot fleame runneth out at the nose:and if it falleth to the lungs, the asse dieth, & this beast flyeth more colde then all other beasts, and is not found in the Countries of the North. And joynts of the ridge boane be more strong of the Asse, & stronger bound with sinewes behind about the reines then before. And therfore the Asses beare more heavy burthens behinde about the reines then before about the shoulders. After evennesse of the day and night in springing time [equinox], the Asse is mooved to lethery, and then he roreth & exciteth the female to love with dreadfull roring & strong, and draweth in breath and winde, and bringeth odour and smell of the female to his nose, & by drawing thereof his desire of lerherye burneth, as Plinius saith. And the Asse hath another wretched condition knowen nigh to all men. For he is put to travaile over night, & is beaten with staves, and sticked & pricked with prickes, & his mouth is wrong with a Bernacle, and is lead hether & thether, and withdrawne from léese and pasture, that is in his way oft by refraining of the Bernacle, & dyeth at last after vaine travailes, & hath no reward after his death for the service and travaile that he had living, not so much that his owne skinne is left with him, but it is taken awaye, and the carren is throwen out without sepulture or burialls: But it be so much of the carren that by eating and devouring is somtime buried in the wombes of houndes and wolves. - [Batman]