VESALIUS, ANDREAS

(b. Brussels, Belgium, 31 December 1514; d. Zákinthos, Greece, 15 October 1564), medicine.

The date of Vesalius’ birth is derived from a horoscope cast by the Milanese physician Girolamo Cardano, from which it may also be determined that he was born at a quarter to six in the morning. His father, also named Andreas, was an apothecary of the Emperor Charles V and the illegitimate son of Everard van Wesele or Vesalius and as such, was humble member of a family already distinguished for several generations in medical circles. The maiden name of Vesalius’ mother was Isabel Crabbe, and this resemblance to the name of the English poet has given rise to the legend that she was an Englishwoman. The name Crabbe is in fact common in Brabant.

The young Vesalius received his elementary education in Brussels and matriculated at the University of Louvain in February 1530 to pursue the arts course, the necessary prerequisite for entrance into a professional school. It is not known when he decided to study medicine, but such decision could have been related to the emperor’s legitimization of the young man’s father in 1531, which may have encouraged him to carry on his family’s traditional profession.

Since at this time the medical school of Louvain had little repute, Vesalius chose to carry on his medical studies at the more illustrious faculty of the University of Paris, matriculating there probably in September 1533, where he studied with Guinter of Andernach, Jacobus sylvius (Jacques Dubois), and Jean Ferne. Guinter, who in his Institutions anatomicae (1536) spoke very favorably of his student, and Sylvius, an arch-Galenist and later an enemy of Vesalius, each in his own way directed the young man toward anatomical research. Since they were both supporters of the Galenic tradition, it was natural that their student, although he acquired skill in the technique of dissection, remained under the influence of Galenic concepts of anatomy.

The war between France and the Holy Roman Empire compelled Vesalius to leave Paris in 1536. He returned to Louvain, where, with the friendly support of the burgomaster, he was able to reintroduce anatomical dissection, which had not been part of the medical curriculum for many years, and in 1537 he received the degree of bachelor of medicine. While completing his studies he produced his Paraphrasis in nonum librum Rhazae ad Regem Almansorem (Louvain, 1537), in which he compared Muslim and Galenic therapy-to the disadvantage of the former-but sought to preserve the reputation of Rhazes and to reconcile him with the Greeks. A youthful work, of no significance except as an indication of Vesalius’ continued allegiance to Galen, it was nevertheless important enough to its author for him to reprint it in Basel later in the year, on his way to Italy.

In the autumn of 1537 Vesalius enrolled in the medical school of the University of Padua, then the most famous in Europe, where, after two days of examinations, he received the degree of doctor of medicine magna cum laude on 5 December 1537 and on the following day accepted appointment as explicator chirurgiae with the responsibility of lecturing on surgery and anatomy. Immediately thereafter he gave the required annual anatomical lectures and demonstrations, which although Galenic in character were unusual because, contrary to custom, Vesalius himself performed the dissections rather than consigning that task to a surgeon. In addition, he produced four large anatomical charts representing the portal, caval, arterial, and nervous systems, based chiefly on this dissection and intended as a reference work and memory aid for his students when the cadaver was no longer available. These figures were distinctly novel both in their size, which permitted deceptively naturalistic although primarily Galenic portrayals of even the smaller structures, and in their detailed identification of the parts through an elaborately indexed anatomical terminology of Greek, Latin, Arabic, and Hebrew. The theft and subsequent publication of the drawing of the nervous system and the danger of plagiarism of the others led Vesalius to publish the thee remaining drawings, together with three views of the skeleton by the Dutch artist Jan Stephen of Calcar, a student in Titian’s studio. Although without a general title, they are usually referred to as Tabulae anatomicae sex (Venice, 1538).

In the same year Vesalius produced a dissection manual for his students, Institutiones anatomicae secundum Galeni sententiam…per loannem Guinterium Andernachum…ab Abdrea Vesalio…auctiores et emendatiores redditae (Venice, 1538). As the title indicates, this was a revised and augmented edition of the Galenically oriented dissection manual of his former teacher in Paris, Guinter of Andernach. The revisions display a concern with the minutiae of dissection technique, and the augmentations offer several independent anatomical judgments, such as the briefly expressed but clearly anti-Galenic observation that the cardiac systole is synchronous with the arterial pulse.

Also in 1538 Vesalius visited Matteo Corti, professor of medicine in Bologna, and discussed the problems of therapy by venesection. Differences of opinion between the two men seem to have been the impulse behind Vesalius’ next book, Epistola docens venam axillarem dextri cubiti in dolore laterali secundam (Basel, 1539), written in support of the revived classical procedure first advocated in a posthumous publication (1525) of the Parisian physician Pierre Brissot. In this procedure blood was drawn from a site near the location of the ailment, in contrast to the Muslim and medieval practice of drawing blood from a distant part of the body. As the title of his book indicates, Vesalius sought to locate the precise site for venesection in pleurisy within the framework of the classical method. The real significance of the book lay in Vesalius’ attempt to support his arguments by the location and continuity of the venous system rather than by an appeal to earlier authority. Despite his own still faulty knowledge, his method may be called scientific in relation to that of others; certainly it was nontraditional and required that his opponents resort to the same method if they wished to reply effectively. With this novel approach to the problem of venesection Vesalius posed the then striking hypothesis that anatomical dissection might be used to test speculation. Here too he declared clearly, on the basis of vivisection, that cardiac systole was synchronous with arterial expansion and for the first time mentioned his initial efforts in the preparation of the anatomical monograph that was ultimately to take shape as De humani corporis fabrica.

These activities and the novelty of Vesalius’ teaching were greatly appreciated by both the teachers and students of the university. Indeed, the official document by which the young anatomist was reappointed in 1539 to the medical faculty, with a considerable increase in salary, declared that “he has aroused very great admiration in all the students.” Although the opportunities for dissection were limited by the small number of cadavers available, by 1538, from his lecturing on Galen and his own dissecting, Vesalius began to realize that there were contradictions between Galen’s texts and his own observations in the human body.

In 1539 his supply of dissection material became much greater when Marcantonio Contarini, judge of the Paduan criminal court, became interested in Vesalius’ investigations and made the bodies of executed criminals available to him—occasionally delaying executions to suit the convenience of the young anatomist. For the first time Vesalius had sufficient human material to make and to repeat detailed and comparative dissections. As a result, he became increasingly convinced that Galen’s description of human anatomy was basically an account of the anatomy of animals in general and was often erroneous insofar as the human body was concerned. During the winter of 1539 he was sufficiently sure of his position to challenge the validity of Galenic anatomy in Padua and shortly thereafter to repeat the challenge in Bologna.

Vesalius went to Bologna in January 1540, at the invitation of the medical students of that city, to present a series of anatomical demonstrations, in the course of which he boldly declared that human anatomy could be learned only from the dissection and observation of the human body. As proof of the nonhuman source of Galen’s anatomy he articulated ape and human skeletons and demonstrated that Galen’s description of the bones agreed only with the former.

On his return to Padua, Vesalius began the composition of the Fabrica in its final form. For the next two years, until the summer of 1542, he concentrated his efforts on this huge work, sparing no expenditure of energy or money. He hired the best draftsmen he could find to make the illustrations and the finest Venetian block cutters to reproduce them. To print the book he chose Joannes Oporinus of Basel. In the summer of 1542 Vesalius left Padua for Basel to oversee the printing of his book, and the following May he dissected the body of an executed malefactor and articulated the skeleton, which is still preserved in the University of Basel’s anatomical institute.

With the publication of De humani corporis fabrica (Basel, 1543)—in August rather than in June as given in the colophon—and of its Epitome (Basel, 1543; German translation by Albanus Torinus, Basel, 1543), Vesalius, with youthful impetuosity, decided to relinquish his anatomical studies for the practice of medicine. Since there was a long tradition of imperial service in his family, he applied to the Emperor Charles V and received an appointment as physician to the imperial household. It was an unfortunate decision since much of his time was henceforth devoted to the complaints of the gluttonous emperor and, as Vesalius wrote, “to the Gallic disease, gastrointestinal disorders, and chronic ailments, which are the usual complaints of my patients.” The imperial service once entered could not be abandoned; Vesalius remained the emperor’s physician until the latter’s abdication, thirteen years later.

Despite his renunciation of anatomical studies, it was inevitable that Vesalius would soon return to his first interest. In January 1544 he traveled to Pisa to give a series of demonstrations at the invitation of Cosimo I, grand duke of Tuscany, who sought unsuccessfully to retain his services. Thereafter, while acting as a military surgeon in the course of the emperor’s wars, Vesalius never failed to visit any nearby medical school, to participate in postmortem examinations, or to take advantage of any opportunities for anatomical research. In 1546, during an extended visit to Regensburg, he wrote a long letter partly concerned with the discovery and therapeutic use of the chinaroot (Chinae radix) in the treatment of syphilis and partly to justify his anatomically heretical activities against the attack of the Galenic anatomists of Paris, most notably those of his former teacher Sylvius. It was published under the title Epistola rationem modumque propinandi radicis chynae decocti pertractans (Basel, 1546).

During his service with the imperial army Vesalius was able to apply his unrivaled anatomical knowledge to surgery. He learned the emollient treatment of gunshot wounds from the Italian surgeon Bartolomeo Maggi; and although his surgery seems to have been burdened at first by an academic quality not required or even desirable on the battlefield, he quickly learned existing surgical techniques and went on to develop others. His most notable contribution was the introduction, as early as 1547, of surgically induced drainage of empyema, and he became so proficient in this procedure that he was sufficiently confident of the outcome to recommend it to other surgeons. His account of this operation, written as a letter (1562) to Giovanni Filippo Ingrassia of Sicily, was an outstanding contribution to the surgical literature. His reputation as a surgeon became so great that in 1559, when Henry II of France received what was to be a fatal head wound in a tournament. Vesalius was summoned from Brussels and placed in charge of the patient, despite the presence of the distinguished French surgeon Ambroise Paré. Vesalius wrote the report of the case after its termination.

The qualities of mind that had been responsible for the Fabrica brought Vesalius the reputation of being one of the great physicians of his age; his opinion was widely sought in grave medical problems. There are a number of contemporary references to him as “that noble physician” and “the best physician in the world.” An instance of what he considered the proper relation of anatomy to medicine was his remarkable diagnosis and correct prognosis in 1555 of an internal aneurysm in a living patient.

As his experience became greater and as he realized the need for correcting errors of fact and faults of composition in the Fabrica, Vesalius gave more thought to a new edition. It is not known when an agreement was reached with the publisher Oporinus for the costly enterprise, but it was at some time after 1547; and it seems most likely that Vesalius wrote the revised text during an extended sojourn with the emperor in Augsburg between August 1550 and October 1551. However, it was only after a long delay that the revised edition was published in Basel in August 1555.

With the abdication of Charles V in 1555, Vesalius for unknown reasons took service with his son Philip II of Spain as physician to the Netherlanders at the Spanish court and, from time to time, to the king himself. He remained in Spain from 1559 until the year of his death.

At the close of 1561 Vesalius completed a long reply to the Observationes anatomicae (1561) of Gabriele Falloppio, a respectful criticism of certain aspects of the Fabrica, which had been sent to him by the author during the preceding summer. Vesalius’ reply, later published under the title of Anatomicarum Gabrielis Falloppii observationum examen (Venice, 1564), is partly a defense against Falloppio’s criticisms and partly an acceptance of them. In addition, it stated Vesalius’ desire to return to his former chair of anatomy at Padua. During the spring of 1562, on the command of Philip II, Vesalius joined the physicians involved in the care and treatment of Don Carlos, the king’s son and heir, who, as the result of a fall, had received a severe injury to his head and was for long in grave danger.

In 1564 Vesalius left Spain for a trip to the Holy Land. Contrary to various legends, the journey appears to have been undertaken with the friendly approbation of the king, although it is not entirely clear whether Vesalius intended to return to Spain. After a visit to Venice—where he apparently was invited to accept his former chair at padua in succession to Falloppio, who had died—he set sail in March for the Holy Land by way of Cyprus. It is not known precisely when the return voyage was begun, but in any event his ship was delayed by a violent storm. After much hardship it finally reached the island of Zákinthos in October, where Vesalius died and was buried in an unidentified site.

Vesalius produced only one book of great importance, De humani corporis fabrica (1543), to which may be added several complementary works, the Epitome (1543), Epistola rationem modumque propinandi radicis chynae (1546), the revised edition of the Fabrica (1555), and the Examen (1564).

Several motives underlay the composition and publication of the Fabrica. According to Vesalius medicine was properly composed of three parts; drugs, diet, and “the use of the hands,” by which last he referred to surgical practice and especially to its necessary preliminary, a knowledge of human anatomy that could be acquired only by dissecting human bodies with one’s own hands. Through disdain of anatomy, the most fundamental aspect of medicine, or, as Vesalius phrased it, by refusal to lay their hands on the patient’s body, physicians betray their profession and are physicians only in part.

Vesalius hoped that by his example in Padua and especially by his verbal and pictorial presentation in the Fabrica he might persuade the medical world to appreciate anatomy as fundamental to all other aspects of medicine and that, through the application of his principles of investigation, a genuine knowledge of human anatomy would be achieved by others, in contrast to the more restricted traditional outlook and the uncritical acceptance of Galenic anatomy. The very word “fabrica” could be interpreted as referring not only to the structure of the body but to the basic structure or foundation of the medical art as well. Thus, Vesalius directed his work toward the established physician, whom he hoped to attract to the study of anatomy as a major but neglected aspect of a true medicine and, no less important, toward those members of the medical profession who were concerned with the teaching of anatomy and might be induced to forsake their long-accepted traditional methods for those proposed by Vesalius. As anatomy was then taught, he wrote, “there is very little offered to the [students] that could not better be taught by a butcher in his shop.”

The Fabrica was also written to demonstrate the fallacious character of Galenic anatomy and all that it implied. Since Galen’s anatomy was based upon the dissection and observation of animals, it was worthless as an explanation of the human structure; and since previous anatomical texts were essentially Galenic, they likewise were worthless and ought to be disregarded. Human anatomy was to be learned only by dissection and investigation of the human body, the true source of such knowledge. Nevertheless it was desirable that human dissection be accompanied by a parallel dissection of the bodies of other animals in order to show the differences in structure and hence the source of Galen’s errors. “Physicians ought to make use not only of the bones of man but, for the sake of Galen of those of the ape and dog.” It was because of Vesalius that Padua became the first great center of comparative as well as of human anatomical studies, a dual interest that continued to develop under his successors Falloppio, Fabrici, and Casserio.

According to Vesalius, the student or physician ought to carry on these activities himself and should personally dissect the human body. The professor or teacher must also descend from his cathedra, dismiss the surgeon who had formerly performed the actual anatomy, and undertake his own dissecting. Moreover, it was not sufficient to base judgments upon a single dissection: the same dissection should be repeated upon several bodies until the dissector could be certain that his observations did not represent structural anomaly. Even the reader of the Fabrica must not be content to accept Vesalius’ descriptions without question but ought to test them by his own dissections and observations. For this purpose the descriptive chapters of the Fabrica are frequently followed by directions for making one’s own dissection of the part described so as to arrive at an independent conclusion.

Vesalius regarded the Fabrica as the gospel of a new approach to human anatomical studies and a new method of anatomical investigation. In Padua both the gospel and its explications were presented directly by the author. For those elsewhere it was presented through the Fabrica with its long and complete descriptions, its illustrative and diagrammatic guides to aid recognition of details and to supplement the reader’s possible shortage of dissection specimens, and even its indirect encouragement of body snatching if necessary. The work reflects fully Vesalius’ method of instruction from about the end of 1539 through 1542 and represents some of it pictorially on the title page.

The presentation of a new anatomy and anatomical method raised several problems, of which the first was that of terminology. As in the Tabulae anatomicae (1538), Vesalius continued to use terms from several languages but stressed the Greek form wherever possible. If this was not enough for clarity, an extensive description was given to localize the part with reference to other parts, and illustrations of the particular organ or structure were provided. Additionally, as a mnemonic device and for increased comprehension, anatomical structures were related to common objects, the radius, for example, being compared to the weaver’s shuttle and the trapezius muscle to the cowl of the Benedictine monks. Some of Vesalius’ terms are still in use, so that this aspect of his pedagogy plays the same role today as it did in the sixteenth century. Thus the names of two of the auditory ossicles, the incus and malleus, are derived from vesalius’ description of them as “that one somewhat resembling the shape of an anvil [incus]” and “that one resembling a hammer [malleus].” The valve of the left atrioventricular orifice, the mitral valve, “you may aptly compare to a bishop’s miter.”

Vesalius’ greatest contribution to the elucidation of anatomy is to be found in the illustrations to the Fabrica. With the exception of those few diagrammatic illustrations that are known to have been drawn by him there is no positive identification of individual draftsmen. The soundest theory is that they were students from Titian’s studio in Venice. Possibly among them was Jan Stephen of Calcar, who drew the three figures of the skeleton for the published version of Vesalius’ anatomical plates of 1538; but the three skeletons of the Fabrica are so greatly superior to those of the earlier work that it seems unlikely that Calcar was responsible for them.

The anatomical detail of the illustrations and their numbered and lettered explanatory legends make it clear that the drawings were made under the supervision of Vesalius for the specific purpose of clarification of a particular portion of the text. Not only is the quality of draftsmanship and precision of detail immensely superior to that of earlier books but the marginal references to the illustrations, which in some instances relate a textual description to several illustrations located in different parts of the work, are also entirely without precedent. For the first time the pedagogic purpose of illustrations was achieved—so well that unfortunately attention has more recently been centered upon the illustrations to the exclusion of the text, thereby nullifying Vesalius’ purpose and even damaging his reputation. He has, for example, been criticized for the exaggerated upward extension of the rectus abdominis muscle as it appears in the fifth “muscle man,” although the legend accompanying the illustration explains this as having been done deliberately to represent an error of Galenic anatomy. Several such seeming errors are in fact deliberate distortions serving pedagogical purposes; they are not appreciated, however, unless text and illustrations are studied together.

In addition to the title page the most noteworthy illustrations in the Fabrica are the three celebrated skeletal figures and the series of “muscle men” which through their postures were given a dynamic quality that was intentional and specifically referred to by Vesalius. The “muscle men,” shown from the front, side, and back, and displaying in sequence from the surface downward the underlying layers of muscle, were a novelty, although crudely foreshadowed by the series of figures in Berengario da Carpi’s Commentaria (1521); the latter, however, were wholly lacking the elegance and detail to be found in the Vesalian figures.

Owing to the larger amount of dissection material available to him, Vesalius was not compelled to follow the traditional pattern of dissection and description originally established by Mondino (1316). Consequently, book I of the Fabrica opens with a description of the bones. This arrangement was desirable since according to Vesalius the bones are the foundation of the body, the structure to which everything else must be related; and in his anatomical demonstrations he was accustomed to sketch the position of the bones on the surface of the body with charcoal in order to orient the students. The fundamental significance of the bones was further indicated by his reference to the femur, for example, as either the bone itself or the entire leg of which the bone was the basic structure. Moreover, the bones are not only supports for the body; since by their structure and formation they assist and control movement, it is necessary to recognize in them a dynamic quality that Vesalius sought to emphasize by the suggestion of movement in the poses of the skeletons.

The teleological argument that pervades the Fabrica, an inheritance from Galen, is very pronounced in the description of osteology. “By not first explaining the bones anatomists… deter [the student] from a worthy examination of the works of God.” Vesalius did not allow this doctrine of final causes to control his investigations, however, since unlike his medieval predecessors he sought to discover first structure and related function, and only then the ultimate purpose.

In his description of human osteology, the subject of book I, Vesalius made some of his strongest assaults upon Galenic anatomy. He called attention to Galen’s false assertion that the human mandible is formed of two bones and demonstrated the significance of this error as reflecting a dependence upon animal sources. Likewise he pointed to the fact that the Galenic description of the sternum as formed of seven segments is true of the ape but not of the adult human sternum, which has only three. Similarly the “humerus, according to Galen, is with the exception only of the femur, the largest bone of the body. Nevertheless the fibula and tibia are distinctly of greater length than the humerus.” In addition to such criticisms, there is extensive description of osteological detail, which, because much of it was wholly novel, required detailed illustrations, elaborately related by letter and number to the text. Despite some errors of description and occasional references to animal anatomy in the Galenic tradition, this first book represents Vesalian anatomy on the highest level. It concludes with a remarkable chapter on the procedure for preparation of the bones and articulation of the skeleton, since it was essential that a skeleton always be available at the dissection. Such a skeleton is a central figure of the title page.

As he had done with the bones, so Vesalius endeavored in book II to identify and give the fullest possible description of every muscle and its function; and an examination of the “muscle men” indicates the thoroughness with which that task was performed. Unfortunately, his system of identifying muscles numerically according to the part they served was cumbersome in comparison with the method of identification by origin and insertion introduced by Sylvius in 1555 and later revised and improved by the Swiss anatomist Gaspard Bauhin. The first two books represent the major Vesalian achievement in terms of accuracy of description and present the most telling blows against Galenic anatomy. In book II Vesalius also most frequently provided chapters dealing with the dissection procedure used to arrive at his conclusions. The description of the vascular system in book III is less satisfactory because of Vesalius’ failure to master the complexities of distribution of the vessels and because of the close relationship of the vascular system to Galenic physiology. Vesalius was compelled to subscribe to this for lack of any other theories. The errors in the Vesalian description of the distribution of the vessels are due to his reliance on Galen, as the only other writer to have attempted such a description in detail, and to the difficulty of discovering anew the entire vascular arrangement in rapidly putrefying human material. Although Vesalius was partly successful, as, for example, in his account of the interior mesenteric and the hemorrhoidal veins, there are many indications that he was compelled to rely for much of his account on the anatomy of animals. This is clearly apparent in the illustration of the “arterial man,” where the arrangement of the branchings of the aortic arch actually illustrate simian anatomy.

Book IV provides an account of the nervous system. It is introduced by an attempt to clarify and limit the meaning of the word “nerve” to the vehicle transmitting sensation and motion, because “leading anatomists declare that there are three kinds of nerve” : ligament, tendon, and aponeurosis. “From dissection of the body it is clear that no nerve arises from the heart as it seemed to Aristotle in particular and to no few others.” Although Vesalius was obliged to accept the Galenic explanation of nervous action as induced by animal spirit distributed through the nerves from the brain, his examination of the optic nerve led him to the conclusion that the nerves were not hollow, as Galen had asserted. “I inspected the nerves carefully, treating them with warm water, but I was unable to discover a passage of that sort in the whole course of the nerve.”

Vesalius accepted Galen’s classification of the cranial nerves into seven pairs even though he recognized more than that number and described a portion of the trochlear nerve. To avoid confusion he declared that he would “not depart from the enumeration of the cranial nerves that was established by the ancients.” Although he was not wholly successful in his efforts to trace the cranial nerves to their origins, and despite some confusion about their peripheral distribution, the level of knowledge in the text and illustrations was well above that of contemporary works and was not to be surpassed for about a generation. Vesalius was more successful in tracing the spinal nerves, but on the whole the account of the nerves must be described as being of lesser quality than some of the other books.

The description of the abdominal organs in book V is detailed and reasonably accurate. Since he knew of no alternative Vesalius accepted that aspect of Galen’s physiology which placed the manufacture of the blood in the liver. Nevertheless he denied not only that the vena cava takes its origin from the liver but also that the liver is composed of concreted blood. Here his strongest blow against Galen and medieval Galenic tradition was his denial, based on human and comparative anatomy, of the current belief in the liver’s multiple (usually five) lobes. According to Vesalius the number of lobes increased with the descent in the chain of animal life. In man the liver had a single mass, while the livers of monkeys, dogs, sheep, and other animals had multiple lobes that became more numerous and more clearly apparent. This difference once again proved the error of dependence upon nonhuman materials.

Vesalius also denied the erroneous Galenic belief that there was a bile duct opening into the stomach as well as one into the duodenum. In regard to the position of the kidneys, he had begun to move away from the erroneous view expressed in the Tabulae anatomicae that the right kidney was placed higher than the left. Although this error is illustrated in the Fabrica, the text declares that the reverse could also be true. Despite this partial error of traditionalism. Vesalius denied a second traditional opinion that the urine passed through the kidneys by means of a filter device. The filter theory had also been denied by Berengario da Carpi; but Vesalius went a step further by asserting that the “serous blood” was deliberately selected or drawn into the kidney’s membranous body and its “branchings” to be freed of its “serous humor” in the same way that the vena cava was able to select and acquire blood from the portal vein, and that the excrement was then carried by the ureters to the bladder.

The book ends with a discussion of human generation and the organs of reproduction. Although Vesalius denied the medieval doctrine of the seven-celled uterus and declared the traditional representation of the horned uterus to result from the use of animal specimens, his description of the fetus and fetal apparatus was of less significance, reflecting, as he admitted, the lack of sufficient pregnant human specimens.

Book VI describes the organs of the thorax. It is chiefly important for the description of the heart, which Vesalius described as approaching the nature of muscle in appearance, although it could not be true muscle since muscle supplied voluntary motion and the motion of the heart was involuntary. In this instance Vesalian principle bowed to Galenic theory, and recognition of the muscular substance of the heart had to await William Harvey’s investigations in the next century.

Like all his contemporaries Vesalius regarded the heart as formed of two chambers or ventricles. The right atrium was not considered to be a chamber but rather a continuation of the inferior and superior venae cavae, considered as a single, extended vessel; and the left atrium was thought to be part of the pulmonary vein. According to Galen the ventricles were divided by a midwall containing minute openings or pores through which the blood passed or seeped from the right ventricle into the left, an opinion that Vesalius strongly questioned even though by implication he was casting doubt on Galen’s cardiovascular physiology. “The septum of the ventricles having been formed, as I said, of the very thick substance of the heart… none of its pits-at least insofar as can be ascertained by the senses-penetrates from the right ventricle into the left. Thus we are compelled to astonishment at the industry of the Creator who causes the blood to sweat through from the right ventricle into the left through passages which escape our sight.” Finally Vesalius gave strong expression to his opinion of ecclesiastical censorship over the question of the heart as the site of the soul. After referring to the opinions of the major ancient philosophers on the location of the soul, he continued:

Lest I come into collision here with some scandalmonger or censor of heresy, I shall wholly abstain from consideration of the divisions of the soul and their locations, since today… you will find a great many censors of our very holy and true religion. If they hear someone murmur something about the opinions of Plato, Aristotle or his interpreters, or of Galen regarding the soul, even in anatomy where these matters especially ought to be examined, they immediately judge him to be suspect in his faith and somewhat doubtful about the soul’s immortality. They do not understand that this is a necessity for physicians if they desire to engage properly in their art…

The seventh and final book provides a description of the anatomy of the brain, accompanied by a series of detailed illustrations revealing the successive steps in its dissection. Until the time of Vesalius, illustrations of the brain and any accompanying text usually stressed the localization of intellectual activities in the ventricles, with perception in the anterior ventricles, judgment in the middle, and memory in the posterior. Sensation and motion were considered the work of animal spirit produced in a fine network of arteries at the base of the brain, the rete mirabile. The existence of the rete mirabile in the human brain had been questioned by Berengario da Carpi. It was now firmly denied by Vesalius, who showed the belief in this organ to have been the result of dissection of animals, since such an arterial network does in fact exist in ungulates. Vesalius was also the first to state that the ventricles had no function except the collection of fluid. Moreover, he denied that the mind could be split up into the separate mental faculties hitherto attributed to it. As a corollary he intimated that although animal spirit affected sensation and motion, it had nothing at all to do with mental activity-in short he suggested a divorce between the physical and mental animal. The discussion of the brain is concluded by a chapter on the procedure to be followed for its dissection and by a final, separate section on experiments in vivisection, derived and developed mostly from experiments described by Galen. The separate treatment of this latter material indicated a recognition of physiology as a discipline distinct from anatomy.

In the Fabrica Vesalius made many contributions to the body of anatomical knowledge, by description of structures hitherto unknown, by detailed descriptions of structures known only in the most elementary terms, and by the correction of erroneous descriptions. Despite his many errors his contribution was far greater than that of any previous author, and for a considerable time all anatomists, even those unsympathetic to him, were compelled to refer to the Fabrica. Its success and influence can be measured by the shrillness of Galenic apologists, by the plentiful but unacknowledged borrowings of many, and by the avowed indebtedness of the generous few, such as Falloppio. Although Colombo, Falloppio, and Eustachi corrected a number of Vesalius’ errors and in some respects advanced beyond him in their anatomical knowledge, Colombo published his anatomical studies sixteen years after the appearance of the Fabrica, Falloppio eighteen, and Eustachi twenty. Furthermore, they relied heavily upon Vesalius’ work, the detailed nature of which made it relatively easy for others to correct or to make further contributions. Although their accomplishments deserve recognition they were built upon Vesalian foundations.

More important than the anatomical information contained in the Fabrica was the scientific principle enunciated therein. This was beyond criticism, fundamental to anatomical research, and has remained so. It was not difficult to demonstrate Galen’s errors of anatomy, but such a demonstration was only a means to an end. Its significance lay in the reason for those errors: Galen’s attempt to project the anatomy of animals upon the human body. From time to time others had pointed to Galenic errors, but no one had proposed a consistent policy of doubting the authority of Galen or of any other recognized authority until the only true source of anatomical knowledge—dissection and observation of the human structure—had been tested. With the publication of the Fabrica all major investigators of anatomy were compelled to recognize the new principle, even though at first some paid no more than lip service to it.

For medical students and those with limited or no anatomical knowledge Vesalius composed a briefer work, the misnamed Epitome (1543) of the Fabrica. In the Epitome Vesalius returned to the tradition of the Tabulae anatomicae insofar as the illustrations in this work seem to have been considered more important than the text. The text was arranged somewhat differently from that of the Fabrica, since, although the first two chapters deal with bones and muscles, respectively, they are followed by chapters on the digestive system, cardiovascular system, nervous system (here including the brain), and finally the reproductive system. This is the simplified arrangement that Vesalius advocated “for one wholly unskilled in dissection.” Although Vesalius called the work an epitome and declared it a pathway to the Fabrica, such is not the case; the vast text of the greater work could not be compressed into such slight dimensions, and it is certainly not, as he also wrote, a summary. At best it is a condensation of selections from the Fabrica and, hence, not a major scientific work.

The second edition of the Fabrica was considerably altered both in style and to some degree in the arrangement of the contents. The actual alterations of the contents, found chiefly in books V and VI, include the addition of accounts of autopsies performed by Vesalius from 1543 onward, revision and correction of the description of the fetal membranes, and a clear statement that the cardiac septum is impermeable.

The impact of the new Vesalian illustrations was reflected as early as 1538 in such plagiarisms of the Tabulae anatomicae as those published in Paris (1538), Augsburg (1539), Cologne (1539), and Strasbourg (1541). The much more remarkable illustrations of the Fabrica were subject to even greater plagiarism, the first instance being the excellent copperplates of the Flemish engraver Thomas Geminus (1544), published with a slightly altered text of the Eapitome under the title Compendiosa totius anatomie delineatio aere exarata (London, 1545). If we except the uncompleted work of Canano, Geminus’ book has the further distinction of being the first anatomical treatise to contain copper-engraved illustrations. These were republished in London in 1553 and 1559, and by Jacques Grévin in Paris in 1564, 1565, and 1569; the original plates were copied and recopied thereafter for many subsequent editions. One example of the many plagiarisms of the illustrations of the Fabrica is the much reduced, crude woodcut copies that are to be found in Bernardino Montaña de Monserrate’s Libro de anathomia del hombre (1551), where they have, in fact, no relationship to the Galenic text of this first Spanish anatomical treatise in the vernacular. Somewhat better, larger, and more significant copies are to be found in Ambroise Paré’s Anatomie universelle (1561).

More fundamentally influential were the Vesalian principle underlying anatomical investigation, the method, and the contributions to knowledge of human anatomical structures. These were somewhat slower in diffusion and occasionally met opposition, as in Jacobus Sylvius’ violent attack against Vesalius’ anti–Galenism, Vaesani cujusdam calumniarum in Hippocratis Galenique rem anatomicam depulsio (1551) and the later attack of Francesco dal Pozzo, Apologia in anatome pro Galeno contra Andream Vessalium Bruxellensem (1562). Advanced by the successive occupants of the anatomical chair at Padua (Realdo Colombo, Gabriele Falloppio, and Fabrici), the Vesalian principles were thence diffused through Italy and later throughout western Europe. By the beginning of the seventeenth century, with the exception of a few conservative centers such as Paris and some parts of the Empire, Vesalian anatomy had gained both academic and general support.

BIBLIOGRAPHY

The various editions of Vesalius’ writings and most of the literature about him are to be found in Harvey Cushing, A Bio–Bibliography of Andreas Vesalius, 2nd ed. (Hamden. Conn., 1962); more recent papers and studies of importance, some of them the result of the Vesalian celebrations of 1964, are listed in C. D. O’Malley, “A Review of Vesalian Literature,” in History of Science, IV (Cambridge, 1965), 1–14. M .H. Spielmann, The Iconography of Andreas Vesalius (London, 1925), deals with the various likenesses of Vesalius produced since the sixteenth century, although the only genuine portrait known is that in the Fabrica. The standard biography is C.D.O’Malley, Andreas Vesalius of Brussels, 1514–1564 (Berkeley—Los Angeles, 1964); and particular points of importance have been dealt with by Charles Singer, A Prelude to Modern Science (Cambridge, 1946), and Ruben Ericksson, Andreas Vesalius’ first Public Anatomy at Bologna 1540 (Uppsala, 1959). See also Moritz Roth, Andreas Vesalius Bruxellensis (Berlin, 1892).

C. D. O’Malley