Timaeus
framed out of man.
The gods also mingled natures akin to that of man with other
forms and perceptions. Thus trees and plants were created, which
were originally wild and have been adapted by cultivation to our
use. They partake of that third kind of life which is seated
between the midriff and the navel, and is altogether passive and
incapable of reflection.
When the creators had furnished all these natures for our
sustenance, they cut channels through our bodies as in a garden,
watering them with a perennial stream. Two were cut down the
back, along the back bone, where the skin and flesh meet, one on
the right and the other on the left, having the marrow of
generation between them. In the next place, they divided the
veins about the head and interlaced them with each other in order
that they might form an additional link between the head and the
body, and that the sensations from both sides might be diffused
throughout the body. In the third place, they contrived the
passage of liquids, which may be explained in this way:—Finer
bodies retain coarser, but not the coarser the finer, and the
belly is capable of retaining food, but not fire and air. God
therefore formed a network of fire and air to irrigate the veins,
having within it two lesser nets, and stretched cords reaching
from both the lesser nets to the extremity of the outer net. The
inner parts of the net were made by him of fire, the lesser nets
and their cavities of air. The two latter he made to pass into
the mouth; the one ascending by the air-pipes from the lungs, the
other by the side of the air-pipes from the belly. The entrance
to the first he divided into two parts, both of which he made to
meet at the channels of the nose, that when the mouth was closed
the passage connected with it might still be fed with air. The
cavity of the network he spread around the hollows of the body,
making the entire receptacle to flow into and out of the lesser
nets and the lesser nets into and out of it, while the outer net
found a way into and out of the pores of the body, and the
internal heat followed the air to and fro. These, as we affirm,
are the phenomena of respiration. And all this process takes
place in order that the body may be watered and cooled and
nourished, and the meat and drink digested and liquefied and
carried into the veins.
The causes of respiration have now to be considered. The
exhalation of the breath through the mouth and nostrils displaces
the external air, and at the same time leaves a vacuum into which
through the pores the air which is displaced enters. Also the
vacuum which is made when the air is exhaled through the pores is
filled up by the inhalation of breath through the mouth and
nostrils. The explanation of this double phenomenon is as
follows:—Elements move towards their natural places. Now as every
animal has within him a fountain of fire, the air which is
inhaled through the mouth and nostrils, on coming into contact
with this, is heated; and when heated, in accordance with the law
of attraction, it escapes by the way it entered toward the place
of fire. On leaving the body it is cooled and drives round the
air which it displaces through the pores into the empty lungs.
This again is in turn heated by the internal fire and escapes, as
it entered, through the pores.
The phenomena of medical cupping-glasses, of swallowing, and of
the hurling of bodies, are to be explained on a similar
principle; as also sounds, which are sometimes discordant on
account of the inequality of them, and again harmonious by reason
of equality. The slower sounds reaching the swifter, when they
begin to pause, by degrees assimilate with them: whence arises a
pleasure which even the unwise feel, and which to the wise
becomes a higher sense of delight, being an imitation of divine
harmony in mortal motions. Streams flow, lightnings play, amber
and the magnet attract, not by reason of attraction, but because
‘nature abhors a vacuum,’ and because things, when compounded or
dissolved, move different ways, each to its own place.
I will now return to the phenomena of respiration. The fire,
entering the belly, minces the food, and as it escapes, fills the
veins by drawing after it the divided portions, and thus the
streams of nutriment are diffused through the body. The fruits or
herbs which are our daily sustenance take all sorts of colours
when intermixed, but the colour of red or fire predominates, and
hence the liquid which we call blood is red, being the nurturing
principle of the body, whence all parts are watered and empty
places filled.
The process of repletion and depletion is produced by the
attraction of like to like, after the manner of the universal
motion. The external elements by their attraction are always
diminishing the substance of the body: the particles of blood,
too, formed out of the newly digested food, are attracted towards
kindred elements within the body and so fill up the void. When
more is taken away than flows in, then we decay; and when less,
we grow and increase.
The young of every animal has the triangles new and closely
locked together, and yet the entire frame is soft and delicate,
being newly made of marrow and nurtured on milk. These triangles
are sharper than those which enter the body from without in the
shape of food, and therefore they cut them up. But as life
advances, the triangles wear out and are no longer able to
assimilate food; and at length, when the bonds which unite the
triangles of the marrow become undone, they in turn unloose the
bonds of the soul; and if the release be according to nature, she
then flies away with joy. For the death which is natural is
pleasant, but that which is caused by violence is painful.
Every one may understand the origin of diseases. They may be
occasioned by the disarrangement or disproportion of the elements
out of which the body is framed. This is the origin of many of
them, but the worst of all owe their severity to the following
causes: There is a natural order in the human frame according to
which the flesh and sinews are made of blood, the sinews out of
the fibres, and the flesh out of the congealed substance which is
formed by separation from the fibres. The glutinous matter which
comes away from the sinews and the flesh, not only binds the
flesh to the bones, but nourishes the bones and waters the
marrow. When these processes take place in regular order the body
is in health.
But when the flesh wastes and returns into the veins there is
discoloured blood as well as air in the veins, having acid and
salt qualities, from which is generated every sort of phlegm and
bile. All things go the wrong way and cease to give nourishment
to the body, no longer preserving their natural courses, but at
war with themselves and destructive to the constitution of the
body. The oldest part of the flesh which is hard to decompose
blackens from long burning, and from being corroded grows bitter,
and as the bitter element refines away, becomes acid. When tinged
with blood the bitter substance has a red colour, and this when
mixed with black takes the hue of grass; or again, the bitter
substance has an auburn colour, when new flesh is decomposed by
the internal flame. To all which phenomena some physician or
philosopher who was able to see the one in many has given the
name of bile. The various kinds of bile have names answering to
their colours. Lymph or serum is of two kinds: first, the whey of
blood, which is gentle; secondly, the secretion of dark and
bitter bile, which, when mingled under the influence of heat with
salt, is malignant and is called acid phlegm. There is also white
phlegm, formed by the decomposition of young and tender flesh,
and covered with little bubbles, separately invisible, but
becoming visible when collected. The water of tears and
perspiration and similar substances is also the watery part of
fresh phlegm. All these humours become sources of disease when
the blood is replenished in irregular ways and not by food or
drink. The danger, however, is not so great when the foundation
remains, for then there is a possibility of recovery. But when
the substance which unites the flesh and bones is diseased, and
is no longer renewed from the muscles and sinews, and instead of
being oily and smooth and glutinous becomes rough and salt and
dry, then the fleshy parts fall away and leave the sinews bare
and full of brine, and the flesh gets back again into the
circulation of the blood, and makes the previously mentioned
disorders still greater. There are other and worse diseases which
are prior to these; as when the bone through the density of the
flesh does not receive sufficient air, and becomes stagnant and
gangrened, and crumbling away passes into the food, and the food
into the flesh, and the flesh returns again into the blood. Worst
of all and most fatal is the disease of the marrow, by which the
whole course of the body is reversed. There is a third class of
diseases which are produced, some by wind and some by phlegm and
some by bile. When the lung, which is the steward of the air, is
obstructed, by rheums, and in one part no air, and in another too
much, enters in, then the parts which are unrefreshed by air
corrode, and other parts are distorted by the excess of air; and
in this manner painful diseases are produced. The most painful
are caused by wind generated within the body, which gets about
the great sinews of the shoulders—these are termed tetanus. The
cure of them is difficult, and in most cases they are relieved
only by fever. White phlegm, which is dangerous if kept in, by
reason of the air bubbles, is not equally dangerous if able to
escape through the pores, although it variegates the body,
generating diverse kinds of leprosies. If, when mingled with
black bile, it disturbs the courses of the head in sleep, there
is not so much danger; but if it assails those who are awake,
then the attack is far more dangerous, and is called epilepsy or
the sacred disease. Acid and salt phlegm is the source of
catarrh.
Inflammations originate in bile, which is sometimes relieved by
boils and swellings, but when detained, and above all when
mingled with pure blood, generates many inflammatory disorders,
disturbing the position of the fibres which are scattered about
in the blood in order to maintain the balance of rare and dense
which is necessary to its regular circulation. If the bile, which
is only stale blood, or liquefied flesh, comes in little by
little, it is congealed by the fibres and produces internal cold
and shuddering. But when it enters with more of a flood it
overcomes the fibres by its heat and reaches the spinal marrow,
and burning up the cables of the soul sets her free from the