Department of History
University of California, Irvine
Instructor: Dr. Barbara J. Becker
Report on the Cause of the Plague
by the University of Paris Medical Faculty
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....
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....
We, the masters of the faculty of medicine at Paris ... have decided to compile, with God's help, a brief compendium of the distant and immediate causes of the present universal epidemic ... and of wholesome remedies; drawing on the opinions of the most brilliant ancient philosophers and modern experts, astronomers as well as doctors of medicine....
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....
Aristotle testifies that this is the case in his book Concerning the causes of the properties of the elements, 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....
Conjunctions of Saturn and Jupiter (1300-1490)
Conjunctions of Saturn and Jupiter (1300-1490)
Albertus Magnus ... says that the conjunction of Mars and Jupiter causes a great pestilence in the air, especially when they come together in a hot, wet sign, as was the case in 1345. For Jupiter, being wet and hot, draws up evil vapors from the earth and Mars, because it is immoderately hot and dry, then ignites the vapors, and as a result there were lightnings, sparks, noxious vapors 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 vapors; which is why the winter was not as cold as it should have been. And Mars was also retrograde and therefore attracted many vapors from the earth and sea which, when mixed with the air, corrupted its substance.
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. This state of affairs generated strong winds ... 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.
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 air corrupt in its substance and not changed in its attributes. 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 vapors.
What happened was that the many vapors 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 vapors 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.
And moreover these winds, which have become so common here, have carried among us ... bad, rotten and poisonous vapors 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 center 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....
We must ... 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 humors, 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.