The Legacy of Greece Part 10

[37] See the companion chapter on _Greek Medicine_.

[38] The surviving fragments of the works of Crateuas have recently been printed by M. Wellmann as an appendix to the text of Dioscorides, _De materia medica_, 3 vols., Berlin, 1906-17, iii. pp.

144-6. The source and fate of his plant drawings are discussed in the same author's _Krateuas_, Berlin, 1897.

Celsus, who flourished about 20 B. C., wrote an excellent work on medicine, but gives all too little glimpse of anatomy and physiology.

Rufus of Ephesus, however, in the next century practised dissection of apes and other animals. He described the decussation of the optic nerves and the capsule of the crystalline lens, and gave the first clear description that has survived of the structure of the eye. He regarded the nerves as originating from the brain, and distinguished between nerves of motion and of sensation. He described the oviduct of the sheep and rightly held that life was possible without the spleen.

The second Christian century brings us two writers who, while scientifically inconsiderable, acted as the main carriers of such tradition of Greek biology as reached the Middle Ages, Pliny and Dioscorides. Pliny (A. D. 23-79), though a Latin, owes almost everything of value in his encyclopaedia to Greek writings. In his _Natural History_ we have a collection of current views on the nature, origin, and uses of plants and animals such as we might expect from an intelligent, industrious, and honest member of the landed cla.s.s who was devoid of critical or special scientific skill. Scientifically the work is contemptible, but it demands mention in any study of the legacy of Greece, since it was, for centuries, a main conduit of the ancient teaching and observations on natural history. Read throughout the ages, alike in the darkest as in the more enlightened periods, copied and recopied, translated, commented on, extracted and abridged, a large part of Pliny's work has gradually pa.s.sed into folk-keeping, so that through its agency the gipsy fortune-teller of to-day is still reciting garbled versions of the formulae of Aristotle and Hippocrates of two and a half millennia ago.

The fate of Dioscorides (flourished A. D. 60) has been not dissimilar.

His work _On Materia Medica_ consists of a series of short accounts of plants, arranged almost without reference to the nature of the plants themselves, but quite invaluable for its terse and striking descriptions which often include habits and habitats. Its history has shown it to be one of the most influential botanical treatises ever penned. It provided most of the little botanical knowledge that reached the Middle Ages. It furnished the chief stimulus to botanical research at the time of the Renaissance. It has decided the general form of every modern pharmacopia. It has practically determined modern plant nomenclature both popular and scientific.

Translated into nearly every language from Anglo-Saxon and Bohemian to Arabic and Hebrew, appearing both abstracted and in full in innumerable beautifully illuminated ma.n.u.scripts, some of which are still among the fairest treasures of the great national libraries, Dioscorides, the drug-monger, appealed to scholasticized minds for centuries. The frequency with which fragments of him are encountered in papyri shows how popular his work was in Egypt in the third and fourth centuries. One of the earliest datable Greek codices in existence is a glorious volume of Dioscorides written in capitals,[39] thought worthy to form a wedding gift for a lady who was the daughter of one Roman emperor and the betrothed of a second.[40] The ill.u.s.trations of this fifth-century ma.n.u.script are a very valuable monument for the history of art and the chief adornment of what was once the Royal Library at Vienna[41] (figs.

9-10). Ill.u.s.trated Latin translations of Dioscorides were in use in the time of Ca.s.siodorus (490-585). A work based on it, similarly ill.u.s.trated, but bearing the name of Apuleius, is among the most frequent of mediaeval botanical doc.u.ments and the earliest surviving specimen is contemporary with Ca.s.siodorus himself.[42] After the revival of learning Dioscorides continued to attract an immense amount of philological and botanical ability, and scores of editions of his works, many of them n.o.bly ill.u.s.trated, poured out of the presses of the sixteenth and seventeenth centuries.

[Ill.u.s.tration: Fig. 9 S?G??S ???F???S {SOGKOS TRYPHEROS} = _Crepis paludosa_, _Mn._]

[Ill.u.s.tration: Fig. 10 G??????? {GERANION} = _Geranium pyrenaic.u.m_, _L._

Fifth-century drawings from JULIANA ANICIA M.S., copied from originals of first century B. C. (?)]

[39] The ma.n.u.script in question is Med. Graec. 1 at what was the Royal Library at Vienna. It is known as the _Constantinopolita.n.u.s_.

After the war it was taken to St. Mark's at Venice, but either has been or is about to be restored to Vienna. A facsimile of this grand ma.n.u.script was published by Sijthoff, Leyden, 1906.

[40] The lady in question was Juliana Anicia, daughter of Anicius Olybrius, Emperor of the West in 472, and his wife Placidia, daughter of Valentinian III. Juliana was betrothed in 479 by the Eastern Emperor Zeno to Theodoric the Ostrogoth, but was married, probably in 487 when the ma.n.u.script was presented to her, to Areobindus, a high military officer under the Byzantine Emperor Anastasius.

[41] The importance of this ma.n.u.script as well as the position of Dioscorides as medical botanist is discussed by Charles Singer in an article 'Greek Biology and the Rise of Modern Biology', _Studies in the History and Method of Science_, vol. ii, Oxford, 1921.

[42] This ma.n.u.script is at the University Library at Leyden, where it is numbered Voss Q 9.

But the greatest biologist of the late Greek period, and indeed one of the greatest biologists of all time, was Claudius Galen of Pergamon (A.

D. 131-201). Galen devoted himself to medicine from an early age, and in his twenty-first year we hear of him studying anatomy at Smyrna under Pelops. With the object of extending his knowledge of drugs he early made long journeys to Asia Minor. Later he proceeded to Alexandria, where he improved his anatomical equipment, and here, he tells us, he examined a human skeleton. It is indeed probable that his direct practical acquaintance with human anatomy was limited to the skeleton and that dissection of the human body was no longer carried on at Alexandria in his time. Thus his physiology and anatomy had to be derived mainly from animal sources. He is the most voluminous of all ancient scientific writers and one of the most voluminous writers of antiquity in any department. We are not here concerned with the medical material which mainly fills these huge volumes, but only with the physiological views which not only prevailed in medicine until Harvey and after, but also governed for fifteen hundred years alike the scientific and the popular ideas on the nature and workings of the animal body, and have for centuries been embedded in our speech. A knowledge of these physiological views of Galen is necessary for any understanding of the history of biology and illuminates many literary allusions of the Middle Ages and Renaissance.

Between the foundation of the Alexandrian school and the time of Galen, medicine was divided among a great number of sects. Galen was an eclectic and took portions of his teaching from many of these schools, but he was also a naturalist of great ability and industry, and knew well the value of the experimental way. Yet he was a somewhat windy philosopher and, priding himself on his philosophic powers, did not hesitate to draw conclusions from evidence which was by no means always adequate. The physiological system that he thus succeeded in building up we may now briefly consider (fig. 11).

[Ill.u.s.tration: FIG. 11. Ill.u.s.trating Galen's physiological teaching.]

The basic principle of life, in the Galenic physiology, is a _spirit_, _anima_ or _pneuma_, drawn from the general world-soul in the act of respiration. It enters the body through the _rough artery_ (t?a?e?a a?t???a {tracheia arteria}, _arteria aspera_ of mediaeval notation), the organ known to our nomenclature as the trachea. From this trachea the pneuma pa.s.ses to the lung and then, through the _vein-like artery_ (a?t???a f?e?d?? {arteria phlebodes}, _arteria venalis_ of mediaeval writers, the pulmonary vein of our nomenclature), to the left ventricle.

Here it will be best to leave it for a moment and trace the vascular system along a different route.

Ingested food, pa.s.sing down the alimentary tract, was absorbed as chyle from the intestine, collected by the portal vessel, and conveyed by it to the liver. That organ, the site of the innate heat in Galen's view, had the power of elaborating the chyle into venous blood and of imbuing it with a spirit or pneuma which is innate in all living substance, so long as it remains alive, the _natural spirits_ (p?e?a f?s???? {pneuma physikon}, _spiritus naturalis_ of the mediaevals). Charged with this, and also with the nutritive material derived from the food, the venous blood is distributed by the liver through the veins which arise from it in the same way as the arteries from the heart. These veins carry nourishment and _natural spirits_ to all parts of the body. _Iecur fons venarum_, the liver as the source of the veins, remained through the centuries the watchword of the Galenic physiology. The blood was held to ebb and flow continuously in the veins during life.

Now from the liver arose one great vessel, the hepatic vein, from division of which the others were held to come off as branches. Of these branches, one, our _common vena cava_, entered the right side of the heart. For the blood that it conveyed to the heart there were two fates possible. The greater part remained awhile in the ventricle, parting with its impurities and vapours, exhalations of the organs, which were carried off by the _artery-like vein_ (f?ep? a?t????d??

{phleps arteriodes}, the mediaeval _vena arterialis_, our pulmonary artery) to the lung and then exhaled to the outer air. These impurities and vapours gave its poisonous and suffocating character to the breath.

Having parted thus with its impurities, the venous blood ebbed back again from the right ventricle into the venous system. But for a small fraction of the venous blood that entered the right ventricle another fate was reserved. This small fraction of venous blood, charged still with the _natural spirits_ derived from the liver, pa.s.sed through minute channels in the septum between the ventricles and entered the left chamber. Arrived there, it encountered the external pneuma and became thereby elaborated into a higher form of spirit, the _vital spirits_ (p?e?a ??t???? {pneuma zotikon}, _spiritus vitalis_), which is distributed together with blood by the arterial system to various parts of the body. In the arterial system it also ebbed and flowed, and might be seen and felt to pulsate there.

But among the great arterial vessels that sent forth arterial blood thus charged with vital spirits were certain vessels which ascended to the brain. Before reaching that organ they divided up into minute channels, the _rete mirabile_ (p?e?a e??st?? ?a?a {plegma megiston thauma}), and pa.s.sing into the brain became converted by the action of that organ into a yet higher type of spirits, the _animal spirits_ (p?e?a ???????

{pneuma psychikon}, _spiritus animalis_), an ethereal substance distributed to the various parts of the body by the structures known to-day as nerves, but believed then to be hollow channels. The three fundamental faculties (d??ae?? {dynameis}), the _natural_, the _vital_, and the _animal_, which brought into action the corresponding functions of the body, thus originated as an expression of the primal force or pneuma.

This physiology, we may emphasize, is not derived from an investigation of human anatomy. In the human brain there is no _rete mirabile_, though such an organ is found in the calf. In the human liver there is no _hepatic vein_, though such an organ is found in the dog. Dogs, calves, pigs, bears, and, above all, Barbary apes were freely dissected by Galen and were the creatures from which he derived his physiological ideas.

Many of Galen's anatomical and physiological errors are due to his attributing to one creature the structures found in another, a fact that only very gradually dawned on the Renaissance anatomists.

The whole knowledge possessed by the world in the department of physiology from the third to the seventeenth century, nearly all the biological conceptions till the thirteenth, and most of the anatomy and much of the botany until the sixteenth century, all the ideas of the physical structure of living things throughout the Middle Ages, were contained in a small number of these works of Galen. The biological works of Aristotle and Theophrastus lingered precariously in a few rare ma.n.u.scripts in the monasteries of the East; the total output of hundreds of years of Alexandrian and Pergamenian activities was utterly destroyed; the Ionian biological works, of which a sample has by a miracle survived, were forgotten; but these vast, windy, ill-arranged treatises of Galen lingered on. Translated into Latin, Syriac, Arabic, and Hebrew, they saturated the intellectual world of the Middle Ages.

Commented on by later Greek writers, who were themselves in turn translated into the same list of languages, they were yet again served up under the names of such Greek writers as Oribasius, Paul of Aegina, or Alexander of Tralles.

What is the secret of the vitality of these Galenic biological conceptions? The answer can be given in four words. _Galen is a teleologist_; and a teleologist of a kind whose views happened to fit in with the prevailing theological att.i.tude of the Middle Ages, whether Christian, Moslem, or Jewish. According to him everything which exists and displays activity in the human body originates in and is formed by an intelligent being and on an intelligent plan, so that the organ in structure and function is the result of that plan. 'It was the Creator's infinite wisdom which selected the best means to attain his beneficent ends, and it is a proof of His omnipotence that he created every good thing according to His design, and thereby fulfilled His will.'[43]

[43] A good instance of Galen's teleological point of view is afforded by his cla.s.sical description of _the hand_ in the pe??

??e?a? t?? e? a????p?? s?at? ????? {peri chreias ton en anthropou somati morion}, _On the uses of the parts of the body of man_, i. 1.

This pa.s.sage is available in English in a tract by Thomas Bellott, London, 1840.

After Galen there is a thousand years of darkness, and biology ceases to have a history. The mind of the Dark Ages turned towards theology, and such remains of Neoplatonic philosophy as were absorbed into the religious system were little likely to be of aid to the scientific att.i.tude. One department of positive knowledge must of course persist.

Men still suffered from the infirmities of the flesh and still sought relief from them. But the books from which that advice was sought had nothing to do with general principles nor with knowledge as such. They were the most wretched of the treatises that still masqueraded under the names of Hippocrates and Galen, mostly mere formularies, antidotaries, or perhaps at best symptom lists. And, when the depression of the western intellect had pa.s.sed its worst, there was still no biological material on which it could be nourished.

The prevailing interest of the barbarian world, at last beginning to settle into its heritage of antiquity, was with Logic. Of Aristotle there survived in Latin dress only the _Categories_ and the _De interpretatione_, the merciful legacy of Boethius, the last of the philosophers. Had a translation of Aristotle's _Historia animalium_ or _De generatione animalium_ survived, had a Latin version of the Hippocratic work _On generation_ or of the treatises of Theophrastus _On plants_ reached the earlier Middle Ages, the whole mental history of Europe might have been different and the rediscovery of nature might have been antedated by centuries. But this was a change of heart for which the world had long to wait; something much less was the earliest biological gift of Greece. The gift, when it came, came in two forms, one of which has not been adequately recognized, but both are equally her legacy. These two forms are, firstly, the well-known work of the early translators and, secondly, the tardily recognized work of certain schools of minor art.

The earliest biological treatises to become accessible in the west were rendered not from Greek but from Arabic.[44] The first of them was perhaps the treatise pe?? ??? ????se?? {peri myon kineseos}, _On movement of muscles_ of Galen, a work which contains more than its t.i.tle suggests and indeed sets forth much of the Galenic physiological system.

It was rendered into Latin from the Arabic of Joannitius (Hunain ibn Ishaq, 809-73), probably about the year 1200, by one Mark of Toledo. It attracted little attention, but very soon after biological works of Aristotle began to become accessible. The first was probably the fragment _On plants_. The Greek original of this is lost, and besides the Latin, only an Arabic version of a former Arabic translation of a Syriac rendering of a Greek commentary is now known! Such a work appeared from the hand of a translator known as Alfred the Englishman about 1220 or a little later. Neither it nor another work from the same translator, _On the motion of the heart_, which sought to establish the primacy of that organ on Aristotelian grounds, can be said to contain any of the spirit of the master.[45]

[44] The early European translations from the Arabic are tabulated with unparalleled learning by M. Steinschneider, 'Die Europaischen Uebersetzungen aus dem Arabischen bis Mitte des 17. Jahrhunderts', in the _Sitzungsberichte der kais. Akad. der Wissenschaften in Wien_, cxlix and cli, Vienna, 1904 and 1905.

[45] C. H. Haskins, 'The reception of Arabic science in England,'

_English Historical Review_, London, 1915, p. 56.

A little better than these is the work of the wizard Michael the Scot (1175?-1234?). Roger Bacon tells us that Michael in 1230 'appeared [at Oxford], bringing with him the works of Aristotle in natural history and mathematics, with wise expositors, so that the philosophy of Aristotle was magnified among the Latins'.[46] Scott produced his work _De animalibus_ about this date and he included in it the three great biological works of Aristotle, all rendered from an inferior Arabic version.[47] Albertus Magnus (1206-80) had not as yet a translation direct from the Greek to go upon for his great commentary on the _History of animals_, but he depended on Scott. The biological works of Aristotle were rendered into Latin direct from the Greek in the year 1260 probably by William of Moerbeke.[48] Such translations, appearing in the full scholastic age when everything was against direct observation, cannot be said to have fallen on a fertile ground. They presented an ordered account of nature and a good method of investigation, but those were gifts to a society that knew little of their real value.[49]

[46] Roger Bacon, _Opus majus_, edited by J. H. Bridges, 3 vols., London, 1897-1900. Vol. iii, p. 66.

[47] On the Aristotelian translations of Scott see A. H. Querfeld, _Michael Scottus und seine Schrift, De secretis naturae_, Leipzig, 1919; and C. H. Haskins, 'Michael Scot and Frederick II' in _Isis_, ii. 250, Brussels, 1922.

[48] J. G. Schneider, _Aristotelis de animalibus historiae_, Leipzig, 1811, p. cxxvi. L. Dittmeyer, _Guilelmi Moerbekensis translatio commentationis Aristotelicae de generatione animalium_, Dillingen, 1915. L. Dittmeyer, _De animalibus historia_, Leipzig, 1907.

[49] The subject of the Latin translations of Aristotle is traversed by A. and C. Jourdain, _Recherches critiques sur l'age des traductions latines d'Aristote_, 2nd ed., Paris, 1843; M. Grabmann, _Forschungen uber die lateinischen Aristoteles Ubersetzungen des XIII. Jahrhunderts_, Munster i/W., 1916; and F. Wustenfeld, _Die Ubersetzungen arabischer Werke in das Lateinische seit dem XI.

Jahrhundert_, Gottingen, 1877.

Yet the advent of these texts was coincident with a returning desire to observe nature. Albert, with all his scholasticism, was no contemptible naturalist. He may be said to have begun first-hand plant study in modern times so far as literary records are concerned. His book _De vegetabilibus_ contains excellent observations, and he is worthy of inclusion among the fathers of botany. In his vast treatise _De animalibus_, hampered as he is by his learning and verbosity, he shows himself a true observer and one who has absorbed something of the spirit of the great naturalist to whose works he had devoted a lifetime of study and on which he professes to be commenting. We see clearly the leaven of the Aristotelian spirit working, though Albert is still a schoolman. We may select for quotation a pa.s.sage on the generation of fish, a subject on which some of Aristotle's most remarkable descriptions remained unconfirmed till modern times. These descriptions impressed Albert in the same way as they do the modern naturalist. To those who know nothing of the stimulating power of the Aristotelian biological works, Albert's description of the embryos of fish and his accurate distinction of their mode of development from that of birds, by the absence of an allantoic membrane in the one and its presence in the other, must surely be startling. Albert depends on Aristotle--a third-hand version of Aristotle--but does not slavishly follow him.

'Between the mode of development (_anathomiam generationis_) of birds'

and fishes' eggs there is this difference: during the development of the fish the second of the two veins which extend from the heart [as described by Aristotle in birds] does not exist. For we do not find the vein which extends to the outer covering in the eggs of birds which some wrongly call the navel because it carries the blood to the exterior parts; but we do find the vein that corresponds to the yolk vein of birds, for this vein imbibes the nourishment by which the limbs increase.... In fishes as in birds, channels extend from the heart first to the head and the eyes, and first in them appear the great upper parts. As the growth of the young fish increases the alb.u.men decreases, being incorporated into the members of the young fish, and it disappears entirely when development and formation are complete. The beating of the heart ... is conveyed to the lower part of the belly, carrying pulse and life to the inferior members.

'While the young [fish] are small and not yet fully developed they have veins of great length which take the place of the navel-string, but as they grow and develop, these shorten and contract into the body towards the heart, as we have said about birds. The young fish and the eggs are enclosed and in a covering, as are the eggs and young of birds. This covering resembles the dura mater [of the brain], and beneath it is another [corresponding therefore to the pia mater of the brain] which contains the young animal and nothing else.'[50]

[50] The enormous _De Animalibus_ of Albert of Cologne is now available in an edition by H. Stadler, _Albertus Magnus De Animalibus Libri XXVI nach der colner Urschrift_, 2 vols., Munster i/W., 1916-21. The quotation is translated from vol. i, pp. 465-6.

In the next century Conrad von Megenberg (1309-98) produced his _Book of Nature_, a complete work on natural history, the first of the kind in the vernacular, founded on Latin versions, now rendered direct from the Greek, of the Aristotelian and Galenic biological works. It is well ordered and opens with a systematic account of the structure and physiology of man as a type of the animal creation, which is then systematically described and followed by an account of plants. Conrad, though guided by Aristotle, uses his own eyes and ears, and with him and Albert the era of direct observation has begun.[51]

[51] Conrad's work is conveniently edited by H. Schultz, _Das Buch der Natur von Conrad von Megenberg, die erste Naturgeschichte in deutscher Sprache, in Neu-Hochdeutsche Sprache bearbeitet_, Greifswald, 1897. Conrad's work is based on that of Thomas of Cantimpre (1201-70).

But there was another department in which the legacy of Greece found an even earlier appreciation. For centuries the ill.u.s.trations to herbals and bestiaries had been copied from hand to hand, continuing a tradition that had its rise with Greek artists of the first century B. C. But their work, copied at each stage without reference to the object, moved constantly farther from resemblance to the original. At last the ill.u.s.trations became little but formal patterns, a state in which they remained in some late copies prepared as recently as the sixteenth century. But at a certain period a change set in, and the artist, no longer content to rely on tradition, appeals at last to nature. This new stirring in art corresponds with the new stirring in letters, the Arabian revival--itself a legacy of Greece, though sadly deteriorated in transit--that gave rise to scholasticism. In much of the beautiful carved and sculptured work of the French cathedrals the new movement appears in the earlier part of the thirteenth century. At such a place as Chartres we see the attempt to render plants and animals faithfully in stone as early as 1240 or before. In the easier medium of parchment the same tendency appears even earlier. When once it begins the process progresses slowly until the great recovery of the Greek texts in the fifteenth century, when it is again accelerated.