the early appearance of the heart in the embryo. Corresponding to the
general gradational view that he had formed of Nature, he held that the
most primitive and fundamentally important organs make their appearance
before the others. Among the organs all give place to the heart, which
he considered the first to live and the last to die. In the heart, as
we have seen, he placed the seat of the intelligence.
Thus, not only in his account of the ‘Ladder of Nature’, but also
in his theories of individual development, Aristotle exhibits some
approach to evolutionary doctrine. This is somewhat obscured, however,
by his peculiar view of the nature of procreation. On this topic his
general conclusion is that the material substance of the embryo is
contributed by the female, but that this is mere passive formable
material, almost as though it were the soil in which the embryo grows.
The male, by giving the principle of life, the _soul_ (_psyche_),
contributes the essential generative agency. But this _soul_ is not
material, and it is not, therefore, theoretically necessary for
anything material to pass from male to female. The material which does
in fact pass with the semen of the male is, as the older philosophers
would have said, an _accident_, not an _essential_. The essential
contribution of the male is not matter but _form_ and _principle_.
The female then only provides the _material_, the male the _soul_, the
form, the principle, that which makes life. Aristotle was thus prepared
to accept instances of fertilization without material contact, i.e.,
in effect, _parthenogenesis_ or ‘virgin birth’. In the centuries that
came after him such instances were not infrequently adduced, and this
doctrine was given a special turn by Christian theologians. Belief in
the ‘accidental’ character of the material contribution of the male was
common among men of science till the nineteenth century. The general
attitude as to the nature of fertilization set forth, for instance, by
William Harvey (1578-1657, pp. 111-14) in his book, _On the Generation
of Animals_, published in London in A.D. 1651, is practically identical
with the views of Aristotle published in Athens about 350 B.C., just
2,000 years earlier. It is of great interest to note that very recent
embryological research goes some way to confirm this view of Aristotle.
Without any intervention of the male sexual element, it is possible
so to stimulate the egg mechanically as to produce a perfect animal
which is thus fatherless from the first. The male element is indeed
unnecessary and, in fact, transmits only hereditary characters.
We must say something concerning Aristotle’s conceptions of the nature
of Life itself. He was before all things a ‘vitalist’. For him the
distinction between living and not-living substance is to be sought not
in material constitution, but in the presence or absence of something
that he calls _psyche_, which we may translate ‘Soul’. His teaching on
this topic had the profoundest influence on subsequent anatomical and
physiological thought.
Aristotle’s theory as to the relation of this Soul to material things
is a difficult and complicated subject. Its adequate discussion would
take us beyond our theme. He holds, however, that the Soul is related
to the idea of _form_. In living things the soul is that which gives
form. It is the pervasion by the soul that leads to the determinate
development of the body and its parts. This activity of the Soul, under
the Aristotelian term _Entelechy_ (which we may perhaps translate ‘the
indwelling perfectability’ or ‘purposiveness’, see _Preface_), has an
important place in modern biological theory, which has, indeed, swung
definitely in the direction of the Aristotelian position.
Aristotle defines Life, existing in Matter, as ‘the power of
self-nourishment and of independent growth and decay’. Of the Soul, the
principle of Life, he distinguishes three orders or types, the lowest
_vegetative_, or nutritive and reproductive, next the _animal_ or
sensitive, and highest the _rational_ or intellectual soul. The last,
he at first held, was peculiar to man, but later he modified this view.
[Illustration: FIG. 13. The four _Elements_ in association with the
four _Humors_ and the four _Qualities_.]
The history of the reception of Aristotle’s science by later ages is
very strange to modern eyes. Of all Aristotle’s scientific teachings,
men clung most firmly for many centuries not to his finely thought-out
biological conceptions, but to a doctrine of the constitution of
matter of which the modern student hears nothing. Aristotle, following
more ancient writers, held that there were four primary and opposite
fundamental _Qualities_, the _hot_ and the _cold_, the _wet_ and
the _dry_. These met in binary combination to constitute the four
Essences or Existences which entered in varying proportions into the
constitution of all Matter. The four Essences, or, to give them their
usual name, _Elements_, were _earth_, _air_, _fire_, and _water_. Thus,
water was wet and cold, fire hot and dry, and so forth. With this
theory later writers combined the somewhat similar Hippocratic doctrine
which held that the body was composed of the four ‘Humors’ or liquids:
_blood_, _phlegm_, _black bile_ (melancholy), and _yellow bile_
(choler). Some of the Hippocratic physicians had associated excess of
the Humors with various types of bodily constitution. Their followers
made much of the ‘temperaments’ resulting therefrom, and according
to the prevailing humor they distinguished the sanguine, phlegmatic,
melancholy or choleric temperament (Fig. 34, p. 97).
These conceptions, now departed altogether from our scientific
discipline, still persist embedded in our language. Poetry still uses
such ideas as the ‘raging of the elements’ and ‘elemental forces’.
We may yet speak of a ‘fiery nature’ or an ‘aerial spirit’. We know
what is meant by a _sanguine_ or a _phlegmatic_ temperament, and a
_melancholy_ or _choleric_ disposition, and such words conjure up
real pictures in our minds (Fig. 34). Until it began to be undermined
by Robert Boyle (1627-91) and others in the seventeenth century, the
doctrine of the four elements persisted in its entirety, while ideas
and terms derived from the old humoral pathology can, in fact, be
traced in the medicine of the twentieth century.
The biological activity of the school of Aristotle was continued after
his death by his pupil Theophrastus (372-287 B.C.). Especially the
writings on plants of Theophrastus are instinct with a thoroughly
scientific spirit, and are rightly regarded as the basic documents
of the science of Botany. Nevertheless, his works had little effect
or influence on his contemporaries and successors. With Theophrastus
the purely biological school of Aristotle may be said to come to an
end. The biological sciences ceased, for many centuries, to be studied
for their own sake and became mere handmaidens of Medicine. Neither
mistress nor servant was the better for the change.
II
THE HEIRS OF GREECE
(300 B.C. TO A.D. 200.)
§ 1. _The Alexandrian School._
Soon after Aristotle, about 300 B.C., a great medical school was
founded at Alexandria in Egypt. That country had been conquered by
Alexander the Great, after whom the town was named. On Alexander’s
death, Egypt came under the rule of one of his generals, Ptolemy,
who established a dynasty which became extinct with the famous Queen
Cleopatra, thirty years before the Christian era. Alexandria was a
favorite residence of this Greek dynasty and became more Greek than
Egyptian. Ptolemy and his successors were patrons of learning, and
at the Alexandrian school remarkable anatomical and physiological
researches were made. These were the work of Greek physicians who, in
the tradition of their people, were only too wont to associate their
discoveries with sweeping theoretical generalizations, often on very
inadequate bases.
The two earliest medical teachers at Alexandria were also the greatest,
Herophilus of Chalcedon, who flourished about 300 B.C., and his
slightly younger contemporary Erasistratus of Chios. Herophilus may
be regarded as the father of Anatomy, Erasistratus as the father of
Physiology.
Herophilus was probably the first to dissect the human body in public.
He recognized the brain as the central organ of the nervous system and
regarded it as the seat of the intelligence, thus reversing the verdict
of Aristotle on the primacy of the heart. He was the first to grasp the
nature of the nerves, which he distinguished as connected with motion
and sensation (Fig. 98), though he did not separate them clearly from
tendons and sinews. He greatly extended the knowledge of the parts
of the brain. Certain parts of the brain still bear titles which are
translations of those which he gave them. He also made the first clear
distinction between arteries and veins.
At the time of the institution of the Alexandrian medical school, and
for long after, there flourished that view of the structure of the
world known as _atomic_, propounded by the philosopher Democritus
(_c._ 400 B.C.). The chief exponent of the theory was Epicurus
(342-270), whose philosophy was of the order which we should now call
‘materialistic’. For it the only ultimate realities were atoms and
‘the void’, and everything was ultimately expressible in these terms.
Epicurean philosophy was not without its reactions on Medicine at
Alexandria, where its leading exponent was Erasistratus of Chios.
Erasistratus was essentially a rationalist and professed himself a
foe to all mysticism. In the last resort, however, he had to invoke
the idea of Nature as a great artist acting as an external power,
shaping the body according to the ends to which it must act. This is
in contrast with Aristotle’s view of the ‘soul’ as an _Entelechy_ (p.
33), an innate and inherent factor. Erasistratus sought to express
his views in atomic terms, but, to make physiology intelligible, he
added a conception, _Pneumatism_, found also among older thinkers.
Pneumatism is the belief that the phenomena of life are associated with
the existence of a subtle vapor, ‘pneuma’ or spirit, which permeates
the organism, and causes its movements. This subtle vapor is held to
have some affinities with the air we breathe. Pneumatism is, in fact, a
primitive attempt to explain the phenomena of respiration.
Erasistratus observed that every organ is equipped with a threefold
system of ‘vessels’, vein, artery, and nerve, which divide to the
very limits of vision, and he considered that the process of division
continues beyond those limits. The minute divisions of these vessels,
plaited together, he believed to make up the tissues. Veins, arteries,
and nerves are, for him, made of minute tubes of the same nature as
themselves, through which they are nourished. Blood and two kinds of
pneuma are the essential sources of nourishment and movement. The blood
is carried by veins. Air, on the other hand, is taken in by the lungs
and passes to the heart, where it becomes changed into a peculiar
pneuma, the _Vital Spirit_, which is sent to the various parts of the
body by the arteries. This spirit is carried to the brain, in the
cavities or ‘ventricles’ of which it is further changed to a second
kind of pneuma, the _Animal Spirit_. The animal spirit is conveyed to
different parts of the body by the nerves, which are hollow.
In the brain Erasistratus observed the convolutions, noted that they
were more elaborate in man than in animals, and associated this
complexity with the higher intelligence of man. He distinguished
between the main parts of the brain, the ‘cerebrum’ and ‘cerebellum’
(Fig. 100, p. 210), and gave a detailed description of the ‘cerebral
ventricles’ or cavities within the brain and of the ‘meninges’ or
membranes that cover the brain. He considered that the cerebral
ventricles were filled with _Animal Spirit_. (Compare Galen’s scheme,
p. 58.)
Erasistratus attained to a clear view of the action of muscles in
producing movement. He regarded the shortening of muscles as due to
distension by _Animal Spirit_ conveyed to the muscles by the nerves. We
may note that similar theories as to the nature of muscular action were
again set forth, on theoretical grounds, in the seventeenth century by
Descartes (1596-1650, pp. 127-8) and by Borelli (1608-79, pp. 129-30),
but were rebutted by the experiments of Swammerdam (1637-80, p. 123).
We may recall that we are still in the dark as to the mechanism of
contraction of muscle fiber, the structure of which was first revealed
by Leeuwenhoek (1632-1723, Figs. 55-56A, p. 121).
Erasistratus considered the chief cause of disease to be excess
of blood or _Plethora_. Diseases thus caused differ according to
their site. Among them are coughing of blood, epilepsy, pneumonia,
tonsillitis, &c. Most of these diseases could be treated by diminishing
the local supply of blood by starvation. Among his contemporaries and
successors blood-letting was an habitual practice applied to almost
every condition. Erasistratus employed it but rarely, and his followers
banned it altogether. He was consistently opposed to violent remedies.
Among the therapeutic measures which he favored were regulated
exercise, diet, and the vapor bath.
Erasistratus complained that many physicians of his time were not
interested in Hygiene. He therefore wrote a treatise on the subject.
Though he regarded Hygiene as a means of substituting prevention for
cure, this did not prevent him from being extremely careful and precise
in his treatment of cases.
After the first generation or two, the activity of the Alexandrian
medical school flagged, though the city long remained a great teaching
center, and minor medical advances were made. Surgery (cf. Fig. 14)
seems to have languished less than Medicine. The stagnation in medical
matters at Alexandria is in contrast to the continued activity there in
Mathematics, Astronomy, Mechanics and Geography.
With the absorption of Egypt into the Roman Empire in 50 B.C. and
the extinction of the Ptolemaic dynasty by the death of Cleopatra in
30 B.C., Alexandria ceased to have great scientific importance. The
school continued for centuries with restricted activity and devoid
of all originality. Intellectually, it had become subordinate to the
Metropolis. Rome was now mistress of the world and the future of
Medicine must be considered from the point of view of the Roman Empire.
[Illustration:
FIG. 14. INSCRIBED TABLET OF ABOUT 100 B.C. from the wall of the temple
of Kom-Ombos in Upper Egypt. The temple itself was built by Ptolemy
VII (181-146 B.C.), but the carving is later. It is divided into four
partitions. These illustrate the surgical instruments in use in Egypt
during Alexandrian times.
In the partition to the extreme left can be seen two cupping-glasses
(cf. Fig. 8), a case of instruments (cf. Fig. 15), a pair of shears, a
sponge, a probe, a pair of fine forceps, and two knives (cf. Fig. 9).
In the next partition to the right can be seen two large forceps, two
bags or flasks, a strigil, two magic eyes, a pair of scales, and two
growing plants.
In the next partition to the right can be seen several hooks of
different forms, several knives, and two or three pairs of forceps.
In the partition to the extreme right can be seen a bifid probe, a pair
of tongs, a long-bladed knife, probes, a double hook, a saw, a cautery,
and several objects probably intended to represent bandages. ]
§ 2. _Medical Teaching in the Roman Empire._
The original native Roman medical system was quite devoid of scientific
elements and was that of a people of the lower culture. Interwoven,
as is all primitive Medicine, with ideas that trespass on the domains
of religion and magic, it possessed that multitude of ‘specialist
deities’ which was so characteristic of the Roman cults. The entire
external aspect of Roman medicine was changed by the advent of Greek
science. Yet, notwithstanding the large medical field that the Western
Empire provided, and the wide acceptance of Greek medicine by the upper
classes, it is remarkable that the Latin-speaking peoples produced no
eminent physician.
At first scientific medical education at Rome was entirely a matter of
private teaching. The earliest important scientific teacher there was
the Greek Asclepiades of Bithynia (died _c._ 40 B.C.), a contemporary
of the poet Lucretius and, like him, an Epicurean. Asclepiades, like
Erasistratus, imported the atomic view of Democritus into Medicine. He
deeply influenced the course of later medical thought, ridiculed the
Hippocratic attitude of relying on the ‘healing power of nature’ which
he regarded as a mere ‘meditation on death’, and urged that active
measures were needed for the process of cure to be ‘seemly, swift and
sure’. He founded a regular school at Rome which continued after him.
At first the school was the mere personal following of the physician,
who took his pupils and apprentices round with him on his visits. At
a later stage such groups combined to form societies or colleges,
where problems of the art were debated. Towards the end of the reign
of Augustus (27 B.C.-14 A.D.) or the beginning of that of Tiberius
(14 A.D.-37 A.D.), these societies constructed for themselves a
meeting-place on the Esquiline Hill. Finally the emperors built
halls or _auditoria_ for the teaching of Medicine. The professors at
first received only the pupils’ fees. It was not until the time of
the Emperor Vespasian (reigned A.D. 70-9) that medical teachers were
given a salary at the public expense. The system was extended by later
emperors.
Thus Rome became a center of medical instruction. After a time
subsidiary centers were established in other Italian towns. From Italy
the custom spread and we meet traces of such schools at the half-Greek
Marseilles as well as at Bordeaux, Arles, Nîmes, Lyons, and Saragossa.
For the most part these provincial schools produced workaday medical
men, few of whose writings have come down to us. They were perhaps
largely training-places for the army surgeons. That class seldom had
scientific interests, though Dioscorides, one of the most prominent
physicians of antiquity, one who earned the respect of Galen and has
deeply influenced the modern pharmacopoeia, served in the army under
Nero. His book is, in fact, an extremely useful though ill-arranged
compendium of drugs. Dioscorides wrote in Greek, and his work was not
translated into Latin until the sixth century of our era.
The earliest scientific medical work in Latin is the _De re medica_ of
Celsus, which was prepared about A.D. 30. It is in many ways the most
readable and well-arranged ancient medical work that we have. It is,
however, not an original work but a compilation from the Greek, and the
sole surviving part of a complete encyclopaedia of knowledge. Many of
its phrases are closely reminiscent of the _Hippocratic Collection_.
The ethical tone is high and the general line of treatment sensible and
humane. Celsus, though almost forgotten in the Middle Ages, was the
first classical medical writer to be printed (A.D. 1476).
The treatise of Celsus opens with an interesting account of the History
of Medicine. It then passes on to deal with diet and the general
principles of therapeutics and pathology, next it discusses internal
disease, and then turns to external diseases. The last part of the work
is devoted to surgery, and is perhaps the most valuable of the whole.
Celsus professes himself a follower of Asclepiades of Bithynia (p.
41), but, unlike his master, he by no means despises the Hippocratic
_expectant_ method of ‘waiting on the disease’. In many matters we are
struck with
his boldness as a surgeon. Thus he describes plastic operations on the
face and mouth, and the removal of polypus from the nose. He tells too
of the very dangerous operation for extirpating a goiter (p. 303), and
of cutting for stone. He gives an excellent account of what might be
thought the modern operation for removal of tonsils. Noteworthy also
is his description of dental practice which includes the wiring of
loose teeth and an account of a dental mirror. An idea of the surgical
instruments in use in his time can be obtained from those recovered
from Pompeii (Fig. 15).
[Illustration: FIG. 15. ROMAN SURGICAL INSTRUMENTS of the first century
A.D. found at Pompeii.
_a._ Forceps, probably for extracting teeth.
_b._ Small pocket-case of instruments containing sharp spoon,
probe, &c.
_c._ Fine-toothed forceps.
_d._ Trocar and cannula for tapping fluids confined in cavities.
_e._ Speculum for examining orifices and cavities.
_f._ Instrument for dilating wounds that they may be more fully
examined.
]
§ 3. _Medical Services of the Roman Empire._
If, in Medicine itself, the Roman achieved but few advances, in the
organization of medical service, and especially in the department which
deals with public health, his position is far more noteworthy. All
Latin writers on architecture give much attention to the orientation,
position and drainage of buildings. From an early date sanitation and
public health drew the attention of statesmen. Considering the dread of
the neighborhood of marshes on the part of these practical sanitarians
of Ancient Rome, and in view of modern knowledge of the mosquito-borne
character of Malaria (pp. 284-5), it entertaining to find the mosquito
net ridiculed by the poets Horace, Juvenal and Propertius!
Sanitation was a feature of Roman life. Rome was already provided with
_cloacae_ or subterranean sewers in the age of the Tarquins (6th cent.
B.C.). The _Cloaca Maxima_ itself, the main drain of Rome, which is
still in use, dates back to that period.
The antiquity of hygienic ideas is seen in an interdict, by a law
of about 450 B.C., against burials within the city walls and in the
instructions issued to the town officials to attend to the cleanliness
of the streets and to the distribution of water. Among these ancient
laws we may note one attributed to the first king of Rome, which
directed the opening of the body in the hope of extracting a living
child in the case of a woman dying in pregnancy. It is the origin of
the so-called ‘Caesarean section’ on the living mother, the method by
which Caesar himself is said to have been brought into the world. At
the date of these decrees physicians in Rome were either slaves or in
an entirely subordinate position. Their status was improved by Julius
Caesar (102-44 B.C.), who conferred citizenship on all who practised
Medicine at Rome, in order to induce physicians to settle there.
[Illustration: FIG. 16. AQUEDUCT OF NERO. This structure, when
complete, conveyed part of the water-supply of Rome.
(_From an engraving by Piranesi._)]
The finest monument to the Roman care for the public health stands yet
for all to see in the remains of the fourteen great aqueducts which
supplied the city with 300,000,000 gallons of potable water daily. No
modern city is better equipped (Fig. 16).
Under the early Empire a definite public medical service was
constituted. Public physicians were appointed to the various towns and
institutions. A statute of the Emperor Antoninus of about the year A.D.
160 regulates the appointment of these physicians, whose main duty was
to attend to the poor. In the code of the Emperor Justinian (A.D. 533)
is an article urging them to give this service cheerfully rather than
the more subservient attendance on the wealthy. Their salaries were
fixed by the municipal councillors. They were encouraged to undertake
the training of pupils. Inscriptions attest the respect in which these
state physicians were held in many towns.