Points to Ponder:
-- What specific causes of disease does Ibn Ridwan discuss?
-- What similarities and differences exist between this excerpt and the much older theory of Hippocrates?
-- Do you think that Ibn Ridwan is largely basing his ideas on Hippocratic thought?
"As
for the indigenous Egyptian illnesses, we have said enough about
the people and the causes of their illnesses. It is clear that
most of their diseases are diseases of superfluities, and yellow
and raw biles combine with the superfluities. The rest of the
illnesses occur among the people quickly and in close succession,
especially at the end of autumn and the beginning of winter.
"As for epidemic illnesses, we have not discussed anything
of this matter until now. The meaning of epidemic illness is that
it encompasses many people in one land at one time. One type is
called al-mawtan, in which the mortality rate is high. Epidemic
diseases have many causes that may be grouped into four kinds:
a change in the quality of the air, a change in the quality of
the water, a change in the quality of the food, and a change in
the quality of psychic events.
"The quality of the air is changed in two ways: first is
its normal variation, and this does not produce an epidemic illness.
. . . Second, when the change does not follow the normal course,
it creates epidemic illness. . . . If they change according to
habit, they do not create illness. If the change is irregular,
however, epidemic illness occurs. A deviation that changes the
air from its customary nature takes place when the air becomes
hotter, colder, damper, drier, or when a corruption mixes with
it. The state of corruption may occur from a nearby or faraway
place. Hippocrates and Galen said that it is not impossible that
an epidemic disease may occur in the land of the Greeks because
of a corruption that accumulated in Ethiopia, ascended to the
atmosphere, then descended on the Greeks, and caused epidemic
illness among them. The temperament of the air may also be changed
from the normal when a large group of people arrives, whose long
journey has ruined their bodies and whose humors have thus become
bad. Much of their humors mixes with the air, and it is transmitted
to the people, so that epidemic disease becomes evident.
"The water may create epidemic illness if the water is excessive
in its increase or decrease, or if a corrupt substance mixes with
it. The people are forced to drink it, and the air surrounding
their bodies is corrupted by the water as well. This corrupt substance
may mix with the water, either in a nearby or distant place, when
the water's course passes by a battlefield where many dead bodies
are found. Or the river passes by polluted swamps, and it carries
and mixes with this stagnant water.
"Foods produce epidemic illness. If blight attacks the plants,
prices rise and most people are forced to change their foods.
If most of the people increase their consumption of these foods
at one time, as at the festivals, dyspepsia increases and the
people become ill. And if the pastureland and the water of the
animals that we eat are corrupted, it will cause epidemic illness.
"Psychic events create epidemic disease when a common fear
of a ruler grips the people. They suffer prolonged sleeplessness
and worry about deliverance or the possibility of trouble. As
a result, their digestion becomes bad and their natural heat is
changed. Sometimes, people are forced to violent action in such
a condition. When they expect a famine in some years, they increase
their hoarding. Their distress intensifies because of what they
anticipate may happen.
"As set forth, epidemic illnesses take place in Egypt on
account of a corruption that is not customary and befalls the
air, regardless of whether the substance of this corruption is
from the land of Egypt itself or from the lands that border it.
. . . Epidemics may result also from what befalls the Nile when
its increase is excessive, whereupon the increase of moisture,
as well as the decay, is greater than usual. When its inundation
is very inadequate, the air becomes drier than usual, and the
people are obliged to drink the bad water. A rottenness may also
mix with the water that results form a war in Egypt, the Sudan,
or another place where many men die, and a vapor rises from their
corpses into the air and putrefies it. The air's decay reaches
the people of Egypt, or the water flows and carries the decay
with it. In addition, epidemics may happen when prices become
excessive and cause a change in diet, when blight besets the crops,
injury occurs to the rams, or general fear or despair seizes the
people. "Every one of these reasons produces an epidemic
illness. . . ."