Adapted from a course website by Prof. Alexandra Cuffel at: http://www.macalester.edu/~cuffel/plague2.htm [accessed 7 December 2006]
This is the most authoritative contemporary statement of the nature of the plague . . . The full text consists of two parts: three chapters on the causes of the plague, and seven on remedies and regimen. Only the first part is printed here.
[Source: R. Hoeniger, ed., Der Schwarze Tod (Berlin, 1882), appendix III, pp. 152-6.]
Seeing things which cannot be explained, even by the most gifted intellects, initially stirs the human mind to amazement; but after marvelling, the prudent soul next yields to its desire for understanding and, anxious for its own perfection, strives with all its might to discover the causes of the amazing events. For there is within the human mind an innate desire to seize on goodness and truth. As the Philosopher [n. 1] makes plain, all things seek for the good and want to understand. To attain this end we have listened to the opinions of many modern experts on astrology and medicine about the causes of the epidemic which has prevailed since 1345.However, because their conclusions still leave room for considerable uncertainty, we, the masters of the faculty of medicine at Paris, inspired by the command of the most illustrious prince, our most serene lord, Philip, King of France, and by our desire to achieve something of public benefit, have decided to compile, with God’s help, a brief compendium of the distant and immediate causes of the present universal epidemic (as far as these can be understood by the human intellect) and of wholesome remedies; drawing on the opinions of the most brilliant ancient philosophers and modern experts, astronomers as well as doctors of medicine. And if we cannot explain everything as we would wish, for a sure explanation and perfect understanding of these matters is not always to be had (as Pliny says in book II, chapter 39:`some accidental causes of storms are still uncertain, or cannot be explained’), it is open to any diligent reader to make good the deficiency.
We shall divide the work into two parts, in the first of which we shall investigate the causes of this pestilence and whence they come, for without knowledge of the causes no one can prescribe cures. In the second part we shall include methods of prevention and cure. There will be three chapters in the first part, for this epidemic arises from a able cause. One cause is distant and from above, and pertains to the heavens; the other is near and from below and pertains to the earth, and is dependent, causally and effectively, on the first cause. Therefore first chapter will deal with the first cause, the second with the second cause, and the third with the prognostications and signs associated with both of them. There will be two treatises in the second part. The first will deal with medical means of prevention and cure and will be divided into four chapters: the first on the disposition of the air its rectification; the second on exercise and baths; the third on food and drink; the fourth on sleeping and waking, emptiness and fullness the stomach and on the emotions. The second treatise will have three chapters: the first on universal remedies; the second on specific remedies appropriate to different patients; the third on antidotes.
CHAPTER 1 OF THE FIRST PART: CONCERNING THE UNIVERSAL AND DISTANT CAUSE
We say that the distant and first cause of this pestilence was and is the configuration of the heavens. In 1345, at one hour after noon on 20 March, there was a major conjunction of three planets in Aquarius. This conjunction, along with other earlier conjunctions and eclipses, by causing a deadly corruption of the air around us, signifies mortality and famine – and also other things about which we will not speak here because they are not relevant. Aristotle testifies that this is the case in his book Concerning the causes of the properties of the elements,[n. 2] in which he says that mortality of races and the depopulation of kingdoms occur at the conjunction of Saturn and Jupiter, for great events then arise,their nature depending on the trigon in which the conjunction occurs. And this is found in ancient philosophers, and Albertus Magnus in his book, Concerning the causes of the properties of the elements (treatise 2, chapter 1) says that the conjunction of Mars and Jupiter causes a greatpestilence in the air, especially when they come together in a hot, wet sign, as was the case in 1345.[n. 3] For Jupiter, being wet and hot, draws up evil vapours from the earth and Mars, because it is immoderately hot and dry, then ignites the vapours, and as a result there were lightnings, sparks, noxious vapours and fires throughout the air.
<>These effects were intensified because Mars – a malevolent planet, breeding anger and wars – was in the sign of Leo from 6 October 1347 until the end of May this year, along with the head of the dragon, and because all these things are hot they attracted many vapours; which is why the winter was not as cold as it should have been.[n. 4] And Mars was also retrograde and therefore attracted many vapours from the earth and the sea which, when mixed with the air, corrupted its substance.[n. 5] Mars was also looking upon Jupiter with a hostile aspect, that is to say quartile, and that caused an evil disposition or quality in the air, harmful and hateful to our nature.[n. 6] This state of affairs generated strong winds (for according to Albertus in the first book of his Meteora, Jupiter has the property of raising powerful winds, particularly from the south) which gave rise to excess heat and moisture on the earth; although in fact it was the dampness which was most marked in our part of the world. And this is enough about the distant or universal cause for the moment.
CHAPTER 2 OF THE FIRST PART: CONCERNING THE PARTICULAR AND NEAR CAUSE
Although major pestilential illnesses can be caused by the corruption of water or food, as happens at times of famine and infertility, yet we still regard illnesses proceeding from the corruption of the air as much more dangerous. This is because bad air is more noxious than food or drink in that it can penetrate quickly to the heart and lungs to do its damage. We believe that the present epidemic or plague has arisen from corrupt air in its substance, and has not changed in its attributes.[n. 7] By which we wish it be understood that air, being pure and clear by nature, can only become putrid or corrupt by being mixed with something else, that is to say, with evil vapours. What happened was that the many vapours which had been corrupted at the time of the conjunction were drawn up from the earth and water, and were then mixed with the air and spread abroad by frequent gusts of wind in the wild southerly, gales, and because of these alien vapours which they carried the winds corrupted the air in its substance, and are still doing so. And this corrupted air, when breathed in, necessarily penetrates to the heart and corrupts the substance of the spirit there and rots the surrounding moisture, and the heat thus caused destroys the life force, and this is the immediate cause of the present epidemic.[n. 8]
And moreover these winds, which have become so common here, have carried among us (and may perhaps continue to do so in future) bad, rotten and poisonous vapours from elsewhere: from swamps, lakes and chasms, for instance, and also (which is even more dangerous) from unburied or unburnt corpses – which might well have been a cause of the epidemic. Another possible cause of corruption, which needs to be borne in mind, is the escape of the rottenness trapped in the centre of the earth as a result of earthquakes – something which has indeed recently occurred. But the conjunctions could have been the universal and distant cause of all these harmful things, by which air and water have been corrupted.
CHAPTER 3: CONCERNING PROGNOSTICATION AND SIGNS
Unseasonable weather is a particular cause of illness. For the ancients, notably Hippocrates, are agreed that if the four seasons run awry, and do not keep their proper course, then plagues and mortal passions are engendered that year. Experience tells us that for some time the seasons have not succeeded each other in the proper way. Last winter was not as cold as it should have been, with a great deal of rain; the spring windy and latterly wet. Summer was late, not as hot as it should have been, and extremely wet – the weather very changeable from day to day, and hour to hour; the air often troubled, and then still again, looking as if it was going to rain but then not doing so. Autumn too was very rainy and misty. It is because the whole year here – or most of it – was warm and wet that the air is pestilential. For it is a sign of pestilence for the air to be warm and wet at unseasonable times.
Wherefore we may fear a future pestilence here, which is particularly from the root beneath,[n. 9] because it is subject to the evil impress of the heavens, especially since that conjunction was in a western sign. Therefore if next winter is very rainy and less cold than it ought to be, we should expect an epidemic round about late winter and spring – and if it occurs it will be long and dangerous, for usually unseasonable weather is of only brief duration, but when it lasts over many seasons, as has obviously been the case here, it stands to reason that its effects will be longer-lasting and more dangerous, unless ensuing seasons change their nature in the opposite way. Thus if the winter in the north turns out to be cold and dry, the plagues might be arrested.
We have not said that the future pestilence will be exceptionally dangerous, for we do not wish to give the impression that it will be as dangerous here as in southern or eastern regions. For the conjunctions and the other causes discussed above had a more immediate impact on those regions than on ours. However, in the judgement of astrologers (who follow Ptolemy on this) plagues are likely, although not inevitable, because so many exhalations and inflammations have been observed, such as a comet and shooting stars.[n. 10] Also the sky has looked yellow and the air reddish because of the burnt vapours. There has also been much lightning and flashes and frequent thunder, and winds of such violence and strength that they have carried dust storms from the south. These things, and in particular the powerful earthquakes, have done universal harm and left a trail of corruption. There have been masses of dead fish, animals and other things along the sea shore, and in many places trees covered in dust, and some people claim to have seen a multitude of frogs and reptiles generated from the corrupt matter; and all these things seem to have come from the great corruption of the air and earth. All these things have been noted before as signs of plague by numerous wise men who are still remembered with respect and who experienced them themselves.
<>No wonder, therefore, that we fear that we are in for an epidemic. But it should be noted that in saying this we do not intend to exclude the possibility of illnesses arising from the character of the present year – for as the aphorism of Hippocrates has it: a year of many fogs and damps is a year of many illnesses. On the other hand, the susceptibility of the body of the patient is the most immediate cause in the breeding of illnesses, and therefore no cause is likely to have an effect unless the patient is susceptible to its effects. We must therefore emphasize that although, because everyone has to breathe, everyone will be at risk from the corrupted air, not everyone will be made ill by it but only those, who will no doubt be numerous, who have a susceptibility to it; and very few indeed of those who do succumb will escape.
The bodies most likely to take the stamp of this pestilence are those which are hot and moist, for they are the most susceptible to putrefaction. The following are also more at risk: bodies bunged up with evil humours, because the unconsumed waste matter is not being expelled as it should; those following a bad life style, with too much exercise, sex and bathing; the thin and weak, and persistent worriers; babies, women and young people; and corpulent people with a ruddy complexion. However those with dry bodies, purged of waste matter, who adopt a sensible and suitable regimen, will succumb to the pestilence more slowly.
We must not overlook the fact that any pestilence proceeds from the divine will, and our advice can therefore only be to return humbly to God. But this does not mean forsaking doctors. For the Most High created earthly medicine, and although God alone cures the sick, he does so through the medicine which in his generosity he provided. Blessed be the glorious and high God, who does not refuse his help, but has clearly set out a way of being cured for those who fear him. And this is enough of the third chapter, and of the whole first part.
Notes (adapted from the Macalester website cited above):
 The philosopher is Aristotle.
 This work, although credited to Aristotle in the middle ages was not by him. It was the subject of a commentary by Albertus Magnus (Albert the Great d.
1280) which the medical faculty cites in the next sentence.
 The houses of the zodiac are each associated with one of the elements . . . Aquarius is one of the air signs and therefore hot and wet.
 Leo is one of the fire signs – hot and dry – and therefore intensifies the hot/dry characteristics of Mars.
 When observed from the earth against the background of the fixed stars, planets at times appear to loop backwards (to be retrograde) or to stand still. Mars
makes a backward loop in some part of the sky once every 780 days.
 As they move round the heavens, through the twelve houses of the zodiac, the planets’ position relative to each other sometimes takes on particular
significance, whether for good or bad. In these positions the planets are said to be looking at each other, and the positions are known as aspects. For
instance, two planet in opposite houses of the zodiac (i.e. separated by 180° of the 360° circle) are said to be in opposition, and the aspect is malign.
The other aspects are: trine (120° apart, benign), quartile (90° apart, malign) and sextile (60° apart, benign).
 As the authors immediately make clear, they do not mean by this that the nature of the air changed, which would be impossible, but that it was corrupted by
being mixed with bad vapours. . .
 `Spirit’ in these medical tracts has a very precise meaning. It was a substance created by the heart from inhaled air, and was envisaged as an extremely thin,
light vapour, which was carried through the body by the arteries. It was, in a literal and immediate sense, the life force, and without it the body would die.
 By the `root beneath’ the authors mean terrestrial causes as distinct from celestial ones. . .
 No comet was seen before the first plague epidemic and authors are presumably referring to the mysterious “star” which appeared over Paris in
August 1348. . .