Sarah Harder HST 301 Research Paper1 Leonardo da Vinci The Hidden Father of Anatomy or an Overrated Icon? By: Sarah Harder May 7, 2010 HST 301 Sarah Harder HST 301 Research Paper 2 In modern day society, what would substantiate one to be called a skilled “painter, architect, mathematician, city planner, biologist and researcher in optics, while at the same time a civil, military and hydraulic engineer…gifted athlete, a fine musician, and a talented singer?”1 Besides decades of educational training and tens, if not hundreds, of thousands of dollars to finance those years of schooling, one would require an insatiable curiosity and an unfathomable aptitude for learning. A person encompassing characteristics to this extreme degree is unheard of in the present day and age. In the sixteenth century, however, one particular scholar “could claim the job titles of architect, astronomer, botanist, sculptor, anatomist, physiologist, geologist, and physicist, as well as military, mechanical, civil, and aeronautical engineer.”2 Born in 1492 in a town near Florence in Tuscany, Leonardo da Vinci received an education before entering into an apprenticeship in Verrocchio’s workshop where he learned painting and sculpture. At the young age of 20, he was welcomed into the painter’s guild of Florence and thus began his career as an artist. The remainder of his years was spent between Milan, Venice, Rome, and Florence. “Almost 500 years after his death Leonardo da Vinci is still known first and foremost as an artist; [however]… not to acknowledge his other accomplishments is to miss his true genius.”3 He made many astonishing breakthroughs in several areas of study that he explored. “In every category of science,…the first modern presentation is often ascribed to Leonardo.”4 He is often referred to as the quintessential Renaissance man due to his ability to grasp a thorough 1 Bhattacharya, 283. 2 Wise, 100. 3 Ibid. 4 Dibner, 380. Sarah Harder HST 301 Research Paper understanding of multiple content areas and make advancements in several fields through close observation and experimentation. “His genius was not bounded by time and technology. His 3 research and invention extended beyond the realm of knowledge and technology available in the day.”5 Though he lacked contemporary equipment such as x-ray machines and had nothing on which to base his initial knowledge besides a small number of classical texts, he had a drive and passion to seek the answers to questions unknown. Due to the brevity of this paper, the focus shall remain on Leonardo’s advancements in the field of anatomy. Originally, Leonardo, like other leading Renaissance artists, began his work in anatomy to refine the realistic quality of his work. “Renaissance artists were among the first to begin examining corpses superficially to improve their depiction of the human body.”6 In the past, dissections were considered taboo and had been made illegal, so a majority of knowledge obtained by scientists and physicians was purely hypothetical.7 The dawn of the Renaissance replaced the constant reliance on religion and superstition with a renewed sense of confidence in mankind, so that gradually, dissections were made legal. The artist Donatello is given the honor of being the first artist to take interest in the scientific study of the human body, but Leonardo was not far behind. He “performed more than 100 human dissections and, among his works that have been discovered, there are 779 anatomical drawings and sketches.”8 As mentioned before, artists often studied the human body to improve their art; however, Leonardo’s studies continued far beyond what was necessary for his artwork. The purpose for his study of anatomy became much more than to improve his art, 5 Monties, 477. 6 Wise, 100. 7 Ackerman, 208. 8 Xie, 899. Sarah Harder HST 301 Research Paper 4 but became a constant search to find the answers to some of life’s mysteries.9 He blurred the line between his role as an art student and that of a student of science as he continually “breathed life into the inert anatomical form.”10 This is not to say that his works were wholly unflawed. On several accounts, his findings were incorrect and he held to certain medieval ideas that led him to erroneous conclusions. Also, whether accurate or not, an argument stands in the present day academic community as to the importance of Leonardo’s anatomical contributions to society. There is no question as to the greatness of his research; however, the fact that the majority of his works were either lost or remained hidden for 400 years after his death causes some scholars to question the significance of his role on the development of modern anatomy. Of these scholars, one, George Sarton, admits to the genius of Leonardo when he says that he “was one of the greatest men of science in history,” but also highlights that “the world which admired him as an artist did not discover the man of science until many centuries after his death.”11 Nonetheless, Leonardo da Vinci was a man born into a world that was not quite ready for him. According to Sigmund Freud, he “awoke too early in the darkness, while everyone was still asleep.”12 He was responsible for the discovery of major breakthroughs in multiple fields spanning over various facets of society, but the breadth of this article will cover his work in the field of anatomy. Leonardo used his observational skills and artistic imagination to bring new light into the field of anatomy, making advancements so great that several ideas are still accepted today, more than 500 years later. Some scholars contend that his impact on this subject matter is 9 Wise, 100. 10 Toledo-Pereyra, 247. 11 Dibner, 380. 12 Bhattacharya, 283. Sarah Harder HST 301 Research Paper 5 so immense that evidence suggests his legitimacy as the “Hidden Father of Modern Anatomy.”13 To propose such a statement is extreme, but the remainder of this paper will take into consideration the actual influence Leonardo had in the history of anatomy. In his anatomical ventures, what were Leonardo da Vinci’s successes versus his failures; and consequently, what impact did he have on the emergence of modern anatomy? The field of anatomy is incredibly broad, yet Leonardo managed to study almost every aspect, meaning each individual bone, muscle, organ, system, etc. In his lifetime, he wrote in excess of 120 chapters on anatomy, though “the only remaining evidence of his anatomical studies is the extensive collection of sketches with their distinctive mirrored captions.”14 Still, the comparatively few works that remain in circulation were bound together to create six folios of information, published in Oslo between 1911 and 1916.15 To comment on each of his findings would require a far more intensive range than intended for this paper. Consequently, the focus will be on briefly covering Leonardo’s study of osteology, myology, the cardiovascular system, the nervous system, and the respiratory system. I. Osteology First, a survey on Leonardo’s studies of osteology is necessary to grasp the intensity of his curiosity. Osteology is, in essence, the study of bones. Throughout his academic career, Leonardo sought to sketch and define each part of the human body, from head to toe. In this goal, he was successful as his folios contain hundreds of drawings that cover both large factions as well as smaller, individual sectors. For example, one of the more famous sketches portrays 13 Toledo-Pereya, 249. 14 Wise, 100. 15 Dibner, 380. Sarah Harder HST 301 Research Paper various viewpoints of the body from the neck down. Through a variety of subsequent sketches, this is broken down into the vertebrae, the leg, the arm, etc. To get the best overview in such a limited document, one should be exposed to Leonardo’s sketch of the full body, neck down as well as that of the skull. Figure 1, a series of sketches known simply as The Skeleton, represents one of the more 6 successful attempts to convey the skeleton in Figure 1 its entirety. Just by viewing this work, the amount of observation required to yield such a precise depiction is obvious. This is not to suggest, however, that his work is completely accurate. “Although far in advance of anything which had preceded it, this sketch…exhibits certain inaccuracies.”16 The scapula (red), for example, is portrayed slightly too long. Leonardo extends it from the second rib to the tenth rib, and modern day anatomy dictates that it should only reach the seventh rib. He did, however, generate the “first accurate depiction of the http://webtafe.com/juanm/juanm/images/0198 52403x_leonardo-da-vinci_2.jpg vertebral column as well as, for the first time, the correct identification of the proper number vertebrae.”17 His representation of the sternum (blue) includes the manubrium (top yellow section) and the xiphoid process (bottom 16 O’ Malley, 40. 17 Wise, 100. Sarah Harder HST 301 Research Paper yellow section) as part of the sternum, but also three separate entities. He does make a slight 7 error by showing eight connecting ribs when there should only be seven.18 Though discrepancies do exist, they are so few and minute that this sketch is highly accurate considering the time period and resources available to the artist. Leonardo’s sketches of the skull follow this same pattern of amazing accuracy bearing in mind the resources accessible. In fact, this Figure 3 particular drawing is highly precise, with the only possible flaw being an error in the count of teeth. Figure 2 is a highly admired sketch due to its creativity in dividing the skull down the middle so that the “front and maxillary air sinuses (yellow), the nasal cavity (green)…have been exposed on the right half, (viewer’s left)”19 and the “superior and inferior orbital fissures (blue), the supraorbital (orange), supratrochlear (pink), infraorbital (purple) and mental foramina (red)”20 are displayed on the left half (viewer’s right). Creativity aside, this piece was a major development http:/www.drawingsofleonardo.org/images/sk ull2.jpg in the scientific community as it provided an accurate depiction of the skull and all its features. 18 O’ Malley, 40. 19 Ibid., 44. 20 Ibid., 44. Sarah Harder HST 301 Research Paper 8 II. Myology Myology, the study of muscles and muscle tissue, was a second major subject that interested Leonardo. Leonardo’s “study of the musculature began as a study of motion and emotion in art and ended as a physiological study of their action.”21 Like several other Renaissance masters, he began his studies to gain a better understanding of the movement of the human body in order to portray more realistic representations in his artwork. As he continued his research, he acquired a genuine curiosity for anatomy, and his title changed from artist to student. Ultimately, his curiosity was effective as he introduced several innovative ideas to the science community. “He was the first to describe the origins and insertions of muscle groups as Figure 4 well as the first to depict the relationships between agonist and antagonist groups of muscles. In addition (he) described the distinct blood and nervous supply to individual muscles.”22 For the sake of this discussion, two of the more prominent muscle sketches will be discussed to reveal the ways in which Leonardo imitated muscle movement and allowed new insight In Figure 3, Leonardo attempts to demonstrate the movement of muscles http://www.wga.hu/art/l/leonardo/10anat 21 Ibid., 100. om/3should1.jpg 22 Ibid., 100. Sarah Harder HST 301 Research Paper 9 throughout the shoulder region. Take particular notice of the construction of the figure in the top, right corner. This “wire or cord model is a unique characteristic of the work of Leonardo and serves two purposes.”23 Not only does it help to visualize the relationship between the surface and its underlying composition, but it also aids in the demonstration of muscle action. His fixation with muscle movement actually spurred the establishment of individual muscle groups that was previously mentioned. Also mentioned was Leonardo being the first to depict the relationship between agonist and antagonist muscles, which he attempts to do in Figure 4. Look closely at the figure on the right. Leonardo describes this relationship in his notes. “When the two muscles a and r pull, the leg is carried forwards and the two muscles b (and) c are relaxed.”24 In this example, the muscles a and r (blue) are the antagonist muscles, and b and c are the agonist muscles. The function of muscles as either antagonist or agonist varies depending on the position. If a muscle is pulled tight, it is always considered an antagonist. Vice versa, if the muscle is relaxed, then it is an agonist. http://www.taschen.com/media/images/320/default_le onardo_exc_10_0706141027_id_44078.jpg Figure 5 23 O’ Malley, 136. 24 Ibid., 80. Sarah Harder HST 301 Research Paper III. Cardiovascular System 10 The next topic is one which many consider to be Leonardo’s most intriguing contribution, his work on the cardiovascular system. This system is composed of the heart, blood, and blood vessels, and is responsible for delivering oxygen and nutrients throughout the body, while also removing waste. Many scholars agree that one of Leonardo’s biggest downfalls was his failure to recognize the circulation of blood. This was not discovered later by William Harvey. Leonardo did propose the movement of blood throughout the body long before Harvey, but because Harvey hypothesized the existence of capillaries as a connector between arterioles and venues, he was able to prove that the blood worked in a constant cycle. The comprehension of this process is not necessary to grasp this discussion, but it must be realized that this is a vital process for the function of blood circulation and the major barrier Leonardo faced in his studies of the cardiovascular system. Though he reached a standstill regarding blood circulation, this is not to say that his research on the cardiovascular system was wholly unsuccessful. Leonardo “was the first to recognize the four chambers of the heart, to accurately describe the valves, and to elucidate the role of the sinuses of Valsalva.”25 Since his opportunity to partake in dissections were few and far between, as well as the fact that a dissection allowed him no insight into the beating heart and movement of blood, the majority of his findings were the result of lab experiments. For example, in one experiment, he placed a porcine valve inside a glass cylinder, and then facilitated the flow of water colored by marker fluid so that he could have a visual aid for his theory of blood flow.26 25 Wise, 101. 26 Ibid. Sarah Harder HST 301 Research Paper 11 As mentioned, the chance to dissect a human heart was rare; however, Leonardo gained much insight from the dissection of animal hearts. For example, Figure 5 is modeled from the heart of an ox. Unfortunately, the more valuable work is somewhat indistinguishable. It is hard to make out majority of the diagrams, but in the upper right hand corner, Leonardo drew an illustration of his theory of the function of the cardiac valves in which he suggested the opening and closing of valves. The two larger diagrams that are discernible are of opposite views of the complete heart. These were significant because they showed the aortic sinuses of the Valsalva as well as the division of the coronary arteries to a relatively well degree of accuracy.27 Though his drawings were somewhat precise, the accompanying descriptions were quite erroneous. The major hitch was that Leonardo was completely ignorant of the circulation of blood. This lack of information made it difficult for him to understand the function of the heart, which was why his descriptions were indecisive and unfinished. Majority of his work was based on Galen’s theory of ebb and flow. This hypothesis can be summed up as follows: http://www.art-prints-ondemand.com/ kunst/leonardo_da_vinci/the_heart.jpg Figure 6 27 O’ Malley, 216. Sarah Harder HST 301 Research Paper 12 Blood on entering the right ventricle must pass by a one-way valve opening inward, so that only an insignificant portion can relapse into the vena cava whence it came. Some of the blood passes directly from right to left through the interventricular septum. But much, and apparently most, of the blood moves into the arterial vein [our pulmonary artery] past a one-way valve opening outward from the ventricle. On contraction of the thorax, the blood in the arterial vein, its retreat cut off from behind, can only go forward into the arterial system of the lungs [in modern usage, venous].28 The basic idea of this conjecture is that blood flows through the veins to be distributed throughout the heart and body. Actually, the circulation of blood is a process that is offset by the contraction of the heart. The blood is pushed out into one of two complicated routes that eventually circles around to restart continually.29 Leonardo was not able to grasp this concept, and so his work with the cardiovascular system was not very beneficial to the scientific community. IV. The Nervous System The central nervous system, in its most basic form, is a system of organs that sends and retrieves signals throughout the body to coordinate movement. Leonardo’s work on the nervous system can be divided into two categories – early work and later work. His initial drawings were based on medieval preconceptions that were far from accurate. At some point during his research, his notions were swayed by Galenic views, which directed him much closer to contemporary ideas. Leonardo was able to make observations from a whole new perspective and subsequently yield brilliant sketches depicting the arrangement of the nervous system.30 28 Fleming, 18-19. 29 Ibid. 30 O’ Malley, 29. Sarah Harder HST 301 Research Paper Leonardo was the first person to portray the cerebral ventricles to complete accuracy. He devised a method which involved injecting a straw into the brain of an ox and pouring hot wax through the straw, into the ventricles. The wax, upon drying, provided a perfect cast of the brain.31 This is how he was able to create a cast of the ventricles of the brain and accurately depict the human head, as shown in Figure 6. The upper figure illustrates the three ventricles, labeled imprensiva (anterior ventricle), senso commune (third ventricle), and memoria (fourth ventricle).32 Most interesting of these is the senso commune, as it does not physically exist. This title represents the concept of the soul. Leonardo spent his Figure 7 13 http://www.drawingsofleonardo.org/images/brai nphysiology.jpg whole career searching for the tangible location of the soul as he thought it was the center of life. Today, scientists claim the soul as more of an idea rather than a physical entity, and identify this mistake as one of Leonardo’s major oversights. Also portrayed in this sketch is a close-up of seven pairs of cranial nerves (middle diagram) and an expanded view of the human head with the skull and brain detached (bottom diagram). 31 Wise, 101. 32 Pevsner, 218. Sarah Harder HST 301 Research Paper Another great contribution Leonardo made to the development of knowledge on the 14 nervous system was the recognition of the importance of the spinal cord. He asserted that serious injury to the spinal cord would result in fatality. He came to this conclusion after conducting several experiments on frogs. He noted that the frogs immediately died after puncturing the spine, yet often managed to survive momentarily without a head, heart, skin, or various internal organs.33 V. The Respiratory System Later in his career, Leonardo spent a great deal of his time studying the respiratory system. Majority of his structural sketches are based exclusively on animal observations, and the physiological composition is spans largely from Galenic theory. He was especially interested in the functioning of the larynx, as he himself was a noted musician. In fact, he credited the larynx to be the most vital organ for the voice and phonation. Figure 7 reveals several various elements of the respiratory system, but the focus shall be on the different viewpoints of the larynx portrayed by Leonardo. The diagram in the top left corner shows the larynx (blue) in relation to the uvula (red). The uvula is the small piece of soft tissue located underneath the tongue, and was believe, according to medieval theory, to facilitate the transmission of phlegm into the larynx so it could lubricate the voice and lungs.34 Leonardo himself discarded this notion, so it is interesting that he chose to include the uvula in his sketch because it seems to suggest his agreement with popularly held vertical relationship. 33 Ibid., 218-219. 34 O’Malley, 386. Sarah Harder HST 301 Research Paper One of the most significant components of this sketch is Leonardo’s recognition of the arytenoids cartilage (purple). The reason for its importance is that it was not said to have been discovered until 1521, by Berengario da Carpi, a famous Bolognese physician and anatomist. This diagram proves that Leonardo, in fact, realized its existence years earlier. Though this was a great discovery for Leonardo, there are still flaws present in this series of sketches. He mistakes tendons emitting from the larynx (yellow) to be nerves that connected to the third ventricle of the http://www.italian-renaissanceart.com/images/Larynx-and-leg-leonardo.jpg Figure 8 15 brain. Also, the size he attributes to the thyroid glands (green) is far too large. This may be due to the fact that his main, and possibly only, observation was through the dissection of animals. VI. Impact on the Formation of Modern Anatomy As evidenced, Leonardo used his amazing art skills to generate astonishing anatomical advancements that superseded the work of his predecessors, as well as several of his successors. Regardless, his hard work was, for the most part, futile because after his death, the majority of Sarah Harder HST 301 Research Paper Leonardo’s sketches were misplaced. For nearly 300 years, his sketches were lost, travelling between various people and places. At present, there is no evidence to suggest that anyone 16 competent enough to comprehend his scientific ideas was ever allowed access to view his work. From traveling around Italy, to wandering throughout Spain and finally England, the journals were disregarded for years because of their indecipherable text and academically advanced drawings.35 It was not until 1796 that the sketches landed in the hands of Sr. William Hunter. Hunter was a renowned anatomist, and said by many modern scholars to be the best human anatomist in eighteenth-century England.36 He realized the value in Leonardo’s sketches and had them combined and published into a set of six folios, collectively titled the Codex. Still today, they remain in the Royal Library at Windsor Castle in England, where Hunter placed them over a century ago.37 The majority of his anatomical works, including those which have been presented in this paper, are published in the Codex Leicester. By this time, however, his “revolutionary breakthroughs” had already been rediscovered and accredited to his successors. Thus, the influence he asserted on the founding of modern anatomy was minute, if it had any impact at all. There is some debate of the possibility that Vesalius, Leonardo’s foremost successor, did have access to his works for a limited time. There was a period of about six years when Leonardo’s sketches were held for public viewing at his close friend Francesco Melzi’s villa home in northern Italy from 1537 to 1545. During this time, Vesalius resided in Italy as a professor of anatomy the University of Padua. He was only 23 years old, and so his career as an anatomist had just began.38 Many scholars contend the possibility that he was able to view 35 Randall, 197. 36 A.K., 950. 37 Keele, 369. 38 Xie, 900. Sarah Harder HST 301 Research Paper 17 Leonardo’s work. This hypothesis is strengthened by the striking similarities and commonalities between the two scientists’ work.39 Leonardo’s sketches were much more detailed and accurate, though Vesalius expanded the borders far beyond what was known pre-Leonardian times.40 Again, this is all just theory among the academic community, and there is no substantial evidence to confirm this idea. So, if this cannot be proven, then it must be assumed to be false. Therefore, the influence of Leonardo on the founding of modern anatomical ideas is diminutive. His real influence, however, was not his actual findings but rather the methods and reasoning he utilized to reach such findings. First off, the fact that he even expended time and effort into carrying out his research was atypical. It had become basically standard practice among the scientific community to acknowledge the theories that had been accepted by previous scholars, usually those stemming from Galen. The fact that Leonardo thought it necessary to challenge the already accepted theories was, in itself, extraordinary. Leonardo “saw when few did the vital necessity of going to nature and freed himself…from the all-powerful Galenic tradition.”41 He rejected the scholarly community’s idea of truth, and instead, sought to achieve his own certainty by acquiring genuine evidence. This in itself constituted an enormous stray for what was perceived as normal, but also led to the introduction of new insight towards conducting scientific experiments.42 Leonardo himself said, “Should you say that the sciences which begin and end in the mind have achieved 39 Randall, 198. 40 Xie, 900. 41 Ochenkowski, 200. 42 Pevsner, 217. Sarah Harder HST 301 Research Paper 18 truth, that I will not concede, but rather deny for many reasons; and first, because in such mental discourse there occurs no experience, without which there is no certainty to be found.”43 Leonardo did not believe that science is a subject that be conjectured in one’s mind. He did not think it feasible to reach accurate conclusions through concepts and ideas. He agreed that these were necessary to form theories, but that these theories must first be tested and proved true before they should be accepted. Basically, he concluded that one must experience the truth or it is not a truth at all. If it is experienced through a first-hand perspective, there is no way to argue its inaccuracy. Leonardo deduced that “nature begins from reason and ends in experience, [but] it is necessary for us to proceed in the opposite direction, commencing…from experience, and by its means investigating the reason.”44 Nature functions in the way it was created to function, and it should be the goal of scientists to observe this functioning and from their observations, make deductions. Again, this opposed the Galenic tradition of making deductions based on no evidence or reasoning. It is not in the nature of mankind to be born with an absolute understanding of the world. It must first be observed before it can be understood. Accordingly, Leonardo completed an astounding amount of observations throughout his academic career. Observation was not wholly uncommon in the scientific community; however, the way that Leonardo viewed the world is the aspect that set him apart from other anatomists. “He appreciated the important fact that the way to understand the structure of an organ was to observe how the organ worked.”45 While other anatomists were concerned solely with depicting 43 Randall, 200. 44 Ibid., 201. 45 Ochenkowski, 200. Sarah Harder HST 301 Research Paper 19 a mirror image of the body, Leonardo felt it necessary to first understand its function. Only then, he concluded, could one correctly portray the image of the body part in question. The process of discerning certain functions of the body was a near impossible task. As mentioned before, man was not born with the innate understanding of the world, so viewing the mechanics of the body was a completely foreign subject. In the past, only slight progress had been made in understanding the human body, and a large part of those conclusions were either partially erroneous or entirely incorrect. Leonardo was able to end this recession in the progress of anatomy by employing a new and different outlook on the functioning of the body. He “insisted on the importance of studying the various tissues entering into a part, as for instance bones, muscles, tendons, vessels, first separately and the collectively, studying each part from all points of view and in all possible positions.”46 This is obvious when viewing his works as one page will contain several sketches of the same body part being studied. The sketches are presented in a variety of different angles and sometimes zoomed in to highlight a specific section of the entity. Leonardo thought that the most promising method to understand the body was to break it down into small pieces. Once he gained an understand of each section, he could put them together and better understand the whole. Leonardo began his endeavors as an artist seeking a way to improve his representation of nature. Hours of dissections and observation, he decided, would generate a more realistic effect on his art by allowing him to portray the human body as more similar to its actual form. By studying the function of muscles and movement, he could arrange his subjects in a variety of positions without losing that life-like appearance. 46 Ibid., 200. Sarah Harder HST 301 Research Paper 20 Regardless of his reasoning, the fact remains that at some point between 1500 and 1506, his interest in anatomy shifted from being a subservient to his art to an “expression of a scientific urge.”47 Leonardo, however, did not view this as a transformation, but rather a merger of two interconnected subjects that would benefit both. The relationship between anatomy and art, he held, would result in considerable progress for both fields. The two were dependent on each other. Leonardo summarizes his beliefs on the relationship between art and anatomy when he says: Painting represents to the senses the works of nature with more truth and certainty than do works or letters; but letters represent works with more truth than painting. But we shall call that science more admirable which represents the works of nature, than that which represents the works of the worker, that is, the works of men, which are words… which come from the human tongue.48 According to Leonardo, painting is the ultimate representation of nature as it is able to depict it in its actual form. It can embody the spirit of nature far more accurately than words could ever describe. The scientific efforts of men, that is words and thoughts, are less commendable those of nature. Given this explanation, it is difficult to deduce whether his varying academic interest can be considered a shift or a merger. At any rate, his new emphasis on anatomy, whether it be a compliment to his art or a new field entirely, resulted in years of rigorous work devoted to seeking the answers to some of hundreds of mysteries presented in the nature of the human body. In this investigation, Leonardo was extremely successful. He far surpassed all his predecessors by refusing to accept their thought-based ideas of the scientific community in the past, and instead establishing his theories according to pure observation. By doing this, he was able to deliver astonishing breakthroughs such as correct depiction of the cerebral ventricles, recognition of the four chambers of the heart, 47 Keele, 360. 48 Randall, 201. Sarah Harder HST 301 Research Paper the acknowledgement of agonist and antagonist muscles, and the identification of the correct number of vertebrae, to name a few. This is not to suggest that Leonardo was a perfect scientist. Throughout his academic career, he made several mistakes. On several occasions, he upheld Galenic theories that were 21 incorrect, thus hindering his progress. The best example of this was his inability to recognize the circulation of blood. He maintained Galen’s ebb and flow theory, which prohibited him from fully recognizing the cardiovascular system. This is but one of the many mistakes made by Leonardo. He also inaccurately depicted the scapula, rib cage, and the thyroid glands. This was largely due to the fact that the majority of his observations were based on the dissection of large animals. This comparative anatomy was helpful, but often led to wrong conclusions. Another major downfall was his constant search for the senso commune, or soul. He believed the senso commune was a physical entity located in the third ventricle of the brain. Nonetheless, his works extended far beyond anything that had been discovered previously. It is unfortunate that his research, more than likely, lied idle for almost 300 years after his death. There is some speculation of the possibility that Vesalius was able to view his sketches, but there is not substantial evidence to confirm this supposition. It was not until 1796 that the sketches ended up in England, in the hands of Sr. William Hunter. He realized the importance of this work and had it published into what is now known as the Codex. Sadly, by this time, all of Leonardo’s great discoveries had already been rediscovered and become accepted ideas so his impact on the formation of modern anatomy was relatively insignificant. His real impact, however, was in the methods he utilized to complete his research. Through observation, dissections, and experimentation, Leonardo was able to transform the scientific world from one based on thoughts and conjectures to one founded on experience. Since Sarah Harder HST 301 Research Paper Leonardo da Vinci’s works were lost after his death, there was no impact on the amount of 22 anatomical knowledge recognized. There was, however, a lasting impact in that scientists began to view the way they looked at science differently, and by placing their reliance on experience rather than speculation, anatomists have reached great conclusions and made much progress in their understanding of the human body. Bibliography Ackerman, James S. “Leonardo Da Vinci: Art in Science.” Daedalus 127, no. 1 (Winter 1998), http://www.jstor.org/stable/20027483. Bhattacharya, Kaushik, and Neele A. Cathrine. “Da Vinci’s Code for Surgeons.” Indian Journal of Surgery 68, no. 5 (October 2006): 283-285. Dibner, Bern. “Leonardo da Vinci, Man of Science.” Science 131, no. 3398 (February 12, 1960), http://www.jstor.org/stable/1705321. Sarah Harder HST 301 Research Paper Fleming, Donald. “Galen on the Motions of the Blood in the Heart and Lungs.” Isis 46, no.1 (March 1955), http://www.jstor.org/stable/226820. K., A. “Leonardo Da Vinci As Anatomist.” The British Medical Journal 1, no. 3673 (May 30, 1931), http://www.jstor.org/stable/25339724. 23 Keele, Kenneth D. “Leonardo Da Vinci’s Influence on Renaissance Anatomy.” Medical History 8, no. 4 (October 1964): 360-370. Monties, Jean-Raoul. “Leonardo da Vinci: Precursor Member of the International Society for Rotary Blood Pumps?” Paper presented at the 6th Congress of the International Society for Rotary Blood Pumps, Park City, Utah, July 25, 1998. O’Malley, Charles D., and J. B. de C. M. Saunders. Leonardo da Vinci on the Human Body. New York: Henry Schuman, Inc., 1952. Ochenkowski, H., and William Wright. “The Quatercentury of Leonardo Da Vinci.” The Burlington Magazine for Connoisseurs 34, no. 194 (May 1919), http://www.jstor.org/stable/860767. Pevsner, Jonathon. “Leonardo da Vinci’s Contributions to Neuroscience.” TRENDS in Neurosciences 25, no. 4 (April 2002): 217-220. Randall, Jr., John Herman. “The Place of Leonardo Da Vinci in the Emergence of Modern Science.” Journal of the History of Ideas 14, no. 2 (April 1953), http://www.jstor.org/stable/2707470. Toledo-Pereyra, Luis H. “Leonardo da Vinci: The Hidden Father of Modern Anatomy.” Journal of Investigative Surgery 15 (2002): 247-249. Wise, M.D., M. Whitten, and J. Patrick O’Leary, M.D. “Leonardo da Vinci: Anatomist and Physiologist.” The American Surgeon 67, no. 1 (January 2001): 100-102. Xie, M.D., Chen, and J. Patrick O’Leary, M.D. “The First Anatomists/Artists.” The American Surgeon 65, no. 1 (September 1999): 899-900.
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