William Harvey

Please Note: In the main text from p.4 onwards, material in black bold Times New Roman font indicates material that was corroborated by two or more sources. Text in any other font indicates material found in only one source. The numbers (1,2) refer to the sources listed in the Bibliography on p. 17.

I have often wondered and even laughed at those who fancied that everything had been so consummately and absolutely investigated by an Aristotle or a Galen or some other mighty name, that nothing could by any possibility be added to their knowledge.”



William Harvey was born on 1st April 1578 at Folkestone, (2,5) [OR] Folkstone (9) Kent, England. (2,3) He was the second oldest (8) [OR] oldest (9,10) of nine children, (8,9) seven brothers (11,12) and two sisters. (11,14) His mother was called Joan Halke (8,10) [OR] Joane (9,12) Hawke (9) [OR] Kent, originally of Hastingleigh, Kent. (12) His father, Thomas Harvey (5,8) was a (5,9) farmer and landowner (11) [OR] a prosperous (6,12) yeoman-farmer (8,12) and later (12) a relatively wealthy (9) Levant Company (12) merchant (5,12) [OR] businessman [OR] and jurat1 (10,14) who became Mayor of Folkestone (9,10) in 1600. (14) He was a calm, diligent, and intelligent man whose “sons … revered, consulted and implicitly trusted in him … (they) made their father the treasurer of their wealth when they acquired great estates … (He) kept, employed, and improved their gainings to their great advantage.” (14) Five of William’s brothers became important merchants in London and one member of parliament for Hythe. (12) William was a 17th (6,7) [OR] 16th (2) Century British (1,2) English (6,7) physician, (1,3) scientist (8) and natural historian (3) who made seminal contributions in anatomy and physiology. (2,3) Harvey is best known for his demonstration of (3,6) the circulation of the blood (1,3) through the functioning of the heart. (10)


William Harvey started his education (9,14) at a small elementary school (9) in Folkestone (9,14) where (10,14) he learned Latin. (9,10) [OR] he learned Latin while boarding with his uncle in Canterbury. (9)

King’s School, Canterbury

In 1588, (11) at age ten, his parents sent him (8,9) to (2,3) the elite (9) King’s (5,6) College (5) [OR] Grammar (8,9) School (6,8) Canterbury. (5,6) While there he lived in his uncle’s home and spent most of his school time learning the classics – Latin was essential throughout Europe for academic and legal work. (9) After 6 years (6) in May (8) 1593 (6,8) at the age of 15 (9) [OR] 16 (2,5) he won a scholarship to pay his living costs and (9) medical (12) tuition fees at university for six years. (9) This medical scholarship, founded by Matthew Parker, Archbishop of Canterbury, was the first such scholarship in England for which preference was given to Kentish Men (Robb-Smith 1971). (12) [OR] Because of his family status, Harvey had no problem obtaining a privileged education. (13)


He was inspired to pursue a degree in medicine, (6,8) and on May 31st 1593 (Booth 2001) (12) he went on to study arts (11) and medicine at (5,8) Gonville and (2,8) Caius College, (2,6) Cambridge. (2,3) because John (12) Caius, one of the founders (8) [OR] refounder (12) of the college, was a noted medical expert. (8) Harvey survived (9,10) on scholarships (10) [OR] a scholarship. (9) He obtained his Bachelor of Arts degree in 15972. (8,10) Caius used to advise his students to seek some part of their medical education abroad, (12) so after graduating (10) in the final two years of the scholarship (9) Harvey travelled to Italy (9,10) and spent some time at universities (9) there and in France and Germany, (9,12) learning more about science and medicine. (9)


In 1600 (8) [OR] 1599 (9,11) when he was 20 (6) [OR] 21 (9) he went to the University of Padua (2,3) in Italy, (5,10) which the same Dr. Caius who helped found Harvey’s college at Cambridge had attended. (13) He wanted a degree in medicine (8,10) and anatomy. (10) Padua was one of the (3) [OR] the (6) pre-eminent medical school in Europe (3,6) acclaimed for its medical and anatomy courses. (9) Copernicus had been a student (12) and Vesalius [OR] Versalius (13) had been Professor of Anatomy there. (3) Interestingly, when Harvey arrived in Padua, Galileo Galilei had already been there for seven years, teaching mathematics, physics and astronomy, (9) but there is no evidence that Galileo and Harvey ever met (Booth 2001). (12) Also at the same time William Shakespeare was completing Hamlet, which most critics regard as his greatest work. (9)

Doctor of Medicine

Harvey completed his studies in Padua, (3,9) and on 25th April (8,11) 1602 (6,7) he graduated as a Doctor of Medicine (6,9) [OR] Doctor of Physic (13) of the University of Padua, Italy. (6,7) His teachers wrote on his diploma:

He had conducted himself so wonderfully well in the examination, and had shown such skill, memory and learning that he had far surpassed even the great hopes which his examiners had formed of him. They decided therefore that he was skilful, expert, and most efficiently qualified both in arts and medicine… (9)

Harvey returned to England in 1602. (9) On his return, the University of Cambridge awarded him a Doctor of Medicine degree, adding to the one he already had from Padua. (6,9)


On his return from Italy in 1602 (5,8) Harvey went to London [OR] Cambridge where he earned yet another degree of Doctor of Medicine from the University. (10,13) The same year, he even became a fellow at his alma mater, Gonville and Caius College. (10)

London and Marriage

He then moved to London to work as a physician. (9,10) He started a medical practice (12) and joined the (9,10) Royal (8) College of Physicians in 1604. (9,10) Harvey sought to become a fellow of the Royal College. (8) A long-held tradition required fellows of the Royal College to have earned an MD degree from Oxford or Cambridge before admittance. (8) On 24th November (8) 1604 (8,10) during his wait for admittance, (8) he married Elizabeth (3,5) C. (12) Browne, daughter of (3,5) Lancelot Browne, (6,8) a physician who served Queen Elizabeth I (3,5) and King James I. (3,11) Harvey and his wife appear to have been happy together, and Harvey referred to her as “my dear deceased loving wife” in his will. (11) He and Elizabeth had no children. (8,9) Harvey established himself as a physician (5) and rapidly gained prominence. (3,6)

Royal College of Physicians

In 1604 (5,6) he obtained a degree (6) [OR] a license to practice (8) at Cambridge. (6,8) On 5th June (8) 1607, [OR] in 1602 (7) he became a fellow of the Royal College of Physicians, (3,5) of London, (6) and remained active in the college throughout his life. (3,9) In 1613, he became censor in the College of Physicians. (12)

St Bartholomew’s Hospital

In 1607 (10) [OR] 1609 (12) he was appointed as an (10,12) assistant (12) physician at St Bartholomew’s Hospital. (10,12) On 14th October (8) 1609, Harvey 5,6) succeeded Ralph Wilkinson in the job of (8) Head (9) Physician at that hospital. (5,6) Harvey earned around thirty-three pounds a year and lived in a small house in Ludgate, although two houses in West Smithfield were attached as fringe benefits to the post of Physician. (14) In addition to his hospital duties and private practice, Harvey was highly involved in teaching and research. (8) The Lumleian lectureship, founded by Lord Lumley and Dr. (14) Richard Caldwell in 1582, consisted

Lumleian Lecturer

In 1615, (9,10) aged 37, (9) he was appointed Lumleian lecturer (6,7) of Surgery (12) at the College of Physicians. (6,7) This was a major leap in his career. (10) The Lumleian lecture series was named after Lord (11,14) John (11) Lumley, (11,14) who, with Dr. Richard Caldwell, had founded it in 1582. (14) The appointed lecturer had to give annual lectures (9,12) which were open to the public, (13) for a period of seven years, with (14) a duty to spread awareness and enhance the general knowledge of anatomy across England. (10) The holder also had to perform an annual public anatomy. (12) He would still continue his work at St Bartholomew’s Hospital. (9,10) He could both teach anatomy (8) [OR] surgery (9) at the College of Physicians, and initiate his research on circulation of the blood. (8) Most of his evidence came from the observations made during his dissection and vivisection of various animals. (8) Harvey began his Lumleian Lectures in April 1616, (12,14) and revealed his findings (5,6) in the first lecture. (6,16) Its manuscript notes contain the first account of blood circulation. (6) [OR] It is likely that Harvey actually made his discovery of the circulation about 1618–19. (11) He continued to give these lectures annually at the College for many years (Booth 2001). (12)

Royal Service

James I

By the time he was 40, Harvey had won recognition as the best physician in London. (9) Another lucrative offer came to him (10) as a result of which, (3,4) on 3rd February (14) 1618 (3,5) he became Physician (3,4) Extraordinary (6,7) to King James I, (3,4) of England and Ireland (and known as King of Scots as James VI). (12) This appointment was a sign of his eminence in the profession and a measure of the useful social connections he had gained through his marriage. (3) He remained in close professional relations to the royal family. (5,7) Harvey led the group of doctors attending James during his last illness, (11) but his and others’ attempts to cure James of his fatal illness failed, and James died in 1625. (12)

Charles I

Harvey was an important witness in the trial of George Villiers, duke of Buckingham, who was accused of poisoning the king. (11) [OR] Harvey became a scapegoat for that failure amidst rumours of a Catholic plot to kill James. (12) He was saved by the personal protection of Charles I, (12) who rewarded him for his care of James. (11) In 1625 (8,10) [OR] 1630 (6) [OR] 1632, (9) aged 54, (2,5) he became physician (6,9) in ordinary (6,10) to King Charles. (6,9) Both James and Charles took a close interest in and encouraged Harvey’s research. (5,10) His close relationship with Charles I served him well as the king supported his research. (8,11) Harvey accompanied Charles I on the latter’s numerous expeditions and hunting adventures, (10) from which he obtained deer (8,10) carcasses (10) from the royal parks (11,12) for his investigations. (8,10) James3 (12) [OR] William (11) took advantage by dissecting the deer. (11,12) He presented interesting medical cases to the king. (11) He made many observations and theories based on the deer. (10) He demonstrated the pumping of the heart on Viscount Montgomery’s son, who had fallen from a horse when he was a boy, leaving a gap in his ribs, subsequently covered by a metal plate, which he was able to remove for Harvey. (12) “I immediately saw a vast hole,” Harvey wrote, “and it was possible to feel and see the heart’s beating through the scar tissue at the base of the hole” (Williams 2004). (12) As appointed court physician and a member of the royal entourage, he was also involved in a number of diplomatic and political activities (Giglioni 2004). (12) In 1629, on the King’s orders, he attended the duke of Lennox in his travels abroad. (12) On several occasions (12) (1633 (6,12), 1639, 1640, 1641), Harvey traveled with the King to Scotland (Giglioni 2004), (12) and he continued to serve the royal family all his life, (3) and also served various royals, aristocrats and bureaucrats, such as Francis Bacon. (10,11)

The Times

It was a period of unparalled intellectual fervor. (13) The year was 1578, and the period has come to be known as the period of the “scientific revolution”. (13) And indeed, it was a revolution, not because of the frequency of scientific discoveries — that prize goes to the present — but because it witnessed a revolution in epistemological thinking, (13)

I have often wondered and even laughed at those who fancied that everything had been so consummately and absolutely investigated by an Aristotle or a Galen or some other mighty name, that nothing could by any possibility be added to their knowledge.” (9)


To fully appreciate the magnitude of Harvey’s revolution, we have to go back in time to the golden age of Greece, around 400 B.C. (13) By that time, the Hellenist civilization had rejected the mythological notions of earlier civilizations that placed everyday events in the hands of spirits in favour of the conviction that events such as rain or disease have natural rather than supernatural causes and that these causes are subject to critical and rational analysis: a transition from “mythos” to “logos,” from mythology to logic or reason. (13) Humans were believed to be made up of the same fundamental elements that comprise all of the cosmos — fire, water, air, and earth. (13) Furthermore, these elements could have the qualities of being hot, cold, dry, and/or moist. (13) The food and drink that animals consumed consisted of these elements, and in the course of digestion they were converted into the bodily juices or humors, namely the blood, phlegm, yellow bile, and black bile, respectively. (13) From these came the descriptors sanguine, phlegmatic, choleric, and melancholic. (13) The relations among the elements that comprise the universe, their qualities, and the humors present in the human according to the ancient model. (13) Hippocrates, considered the founder of Western medicine, maintained that health required the proper balance of these elements; imbalance resulted in disease. (13) Thus, in a sense, Hippocrates and the school of medicine that followed him can be considered the originators of the notion of “homeostasis.” (13)

In this sense, Galen was a true post-Aristotelian who blended a touch of empiricism, in this case anatomic findings, with a large dose of causal or teleological speculation; everything had to serve a purpose or final cause. (13) All parts of the human body are formed in the optimal manner to serve their intended human purposes. (13) Nature is provident, just, and all knowing and does nothing in vain. (13) In the case of the functions of the heart and great vessels, Galen’s model was biased by the heavy emphasis the Greeks placed on the role of a wholesome diet and fresh air in preserving health. (13) Thus the function of the right side of the vasculature was to deliver the products of a healthy diet to the tissues of the body and that of the left side was to deliver fresh air and cool the body. (13)


Galen was born in what is now Turkey but spent most of his adult life and rose to medical fame in Rome. (13) He agreed with Hippocrates that human health required an equilibrium between the four main bodily fluids or humors but regarded anatomy as the foundation of medical knowledge and did many dissections on lower animals; he also served for a short time as the physician to a school of gladiators and so must have seen the human body in various forms of gory disarray. (13) In contrast with Hippocrates, he felt that health depended on the proper balance of humors in specific organs, not only the body as a whole. (13) Galen viewed the body as consisting of three connected systems: the brain and nerves, which were responsible for sensation and thought; the heart and arteries, which were responsible for life-giving energy or “vital spirit”; and the liver and veins, which were responsible for nutrition and growth. (13) Galen said that there were two separate blood systems in the body. (11) Venous blood was thick and dark red [OR] purple (11) “nutritive” (11,12) blood and used the veins to distribute nutrition from the liver to the rest of the body. (11,12) Arterial blood was brighter and thinner (12) scarlet in colour (11) and had a distinct and separate function: it was spiritual and (12) energizing. (11,12) According to Galen, blood was formed in the liver from food carried to that organ from the stomach and intestines via the portal vein. (13) This “natural” blood then entered the systemic veins and was carried to all parts of the body, by an ebb and flow, where it was consumed as nutrient or was transformed into flesh. (13) Thus blood was not conserved; it was constantly being consumed in the periphery and replenished by ingested nutrients, and this was all carried out by the right ventricle and great veins. (13) Note the communication between the right and left ventricles and the independent flows taking place in the venous and arterial vessels. (13) The main task of the left ventricle was to generate a pulsatile force to blood in the arteries, which absorbed “pneuma” or spirit from the lungs. (13) Much of the blood in the left ventricle came directly from the right ventricle through pores in the interventricular septum and some through “leaks” in the pulmonary circulation; the latter were needed to explain the fact that the pulmonary veins contained blood and were not filled with air alone. (13) According to Galen, there was little mingling between arterial and venous blood; each stream had its distinct and essential purpose. (13) The main purpose of the “vital” arterial blood, as distinguished from the “natural” venous blood, was to deliver pneuma or “spiritus vitalus”(13) a life-giving principle from the lungs (11) via the arteries. (11,12) to the peripheral tissues. (13) Some venous blood was thought to seep through the septum of the heart, which was seen as porous, and after arriving in the left ventricle, mix with air from the lungs (Giglioni 2004). (12) Today these blood systems are understood as deoxygenated blood and oxygenated blood. (11) Galen’s errors exercised a ‘pernicious influence’ on medicine. (12) By the time that Harvey began to study medicine, western medical beliefs and theories about blood and circulation had advanced little since Galen wrote his medical textbooks in Rome 1400 years earlier. (9,12)

Ibn al-Nafis

The great (12) 13th-century (11,12) Arabic scholar (14) physician Ibn al-Nafīs (11,12) had disputed aspects of Galen’s views. (14) He provided a model that seems to imply a form of pulmonary circulation (12,14) in his Commentary on Anatomy in Avicenna’s Canon (1242). (14) He stated that blood moved from the heart to the lungs, where it mixed with air, and then back to the heart, from which it spread to the rest of the body. (14) He is widely considered “the father of circulatory physiology,” and some believe the greatest physician in history. (12) Ibn al-Nafis’ descriptions of the pulmonary circulation may have been fairly widespread among Muslim physicians in the Islamic world and he is an important forerunner of Harvey. (12) While Ibn al-Nafis had made great breakthroughs in describing pulmonary circulation in the Muslim world in the 13th century the work of Ibn al-Nafis was ignored in Europe into which Harvey was born because it contradicted what Galen said. (12) Harvey helped to revive the Muslim tradition of scientific medicine expressed by Ibn al-Nafis. (12)

Michael Servetus et al

Some other earlier writers, such as (2,11) Realdo Colombo, (2) 16th-century Spanish physician (11) Michael (2,12) Servetus (2,11) and Jacques Dubois, (2) had provided precursors of a theory of circulation, (2,11) They suggested a “lesser, (11) or pulmonary (12) circulation,” whereby blood circulated from the heart to the lungs and back, without circulating around the whole body. (11) Michael Servetus had also described (12,14) in the Manuscript of Paris in 1546, pulmonary (14) circulation before the time of Harvey, (12,14) but all but three copies of Servetus’ manuscript Christianismi Restitutio4 (12) (the theological work which caused his execution in 1553 (14)) were destroyed and as a result, the secrets of circulation were lost until Harvey rediscovered them nearly a century later. (12)

Hieronymus Fabricius

Hieronymus Fabricius, Harvey’s teacher at Padua, had claimed discovery of “valves” in veins, but had not discovered the true use of them. (12) The explanation that he had put forward did not satisfy Harvey, and thus it became Harvey’s endeavour to explain the true use of these valves, and eventually, the search suggested to him the larger question of the explanation of the motion of blood. (12)

Early Scientists

Harvey was born into an era in which experimentation (the use of the hands) and computation, in addition to simple observation, became recognized as essential tools of the “scientific method.” (13) He was well aware of the work of Copernicus and Kepler, who preceded him, and of his contemporary Galileo, for whom the combination of careful observation and computation resulted in nothing less than a switch between the earth and the sun as the center of our universe; Galileo’s dictum “Measure all that is measurable, and make those things measurable which have hitherto not been measured” was deeply impressed upon him. (13)


His doctoral advisor (2) (tutor) (5) teacher (10) was the Italian (11) scientist, (5) surgeon (5,8) and famed anatomist (6,8) Hieronymus (2,5) [OR] Hieronymous (11) Fabricius (2,5) of Aquapendente. (6,12) Fabricius held a strong interest in Aristotelian views on the formation of the fœtus and the function of valves in the veins. (8) It is said that Fabricius had the single most influence on Harvey’s way of thought, influence that would later be observed in his research. (8,9) The two became friends (9) and Harveywas clearly influenced by the emphasis on experimentation and observation he found at Padua. (3,5) Fabricius was fascinated by anatomy, and had recognised that (5) the veins in the human body had one-way (4,5) stepladder (4) valves, but was puzzled as to their function. (5) He had discovered valves in human veins in 1574, although he did not publish his discovery until 1603. (9) Harvey claimed he was led to his discovery of the circulation by consideration of the venous valves. (7,11) These led Harvey to focus much of his research on the mechanics of blood flow in the human body. (7) It was known that there were small flaps inside the veins that allowed free passage of blood in one direction but strongly inhibited the flow of blood in the opposite direction. (11) It was thought that these flaps prevented pooling of the blood under the influence of gravity, but Harvey was able to show that all these flaps are cardiocentrically oriented. (11) For example, he showed that in the jugular vein of the neck they face downward, inhibiting blood flow away from the heart, instead of upward, inhibiting pooling due to gravity. (11) Harvey learned from Fabricius that dissection offered a route to better understanding of the human body. (9,10) Harvey observed blood flowing through the veins and arteries of living animals that he cut open. (9) Through modern eyes, his living dissections look cruel, and there were no anesthetics in Harvey’s time. (9) Nevertheless, it is how we arrived at an understanding of blood and its circulation in the body. (9)

he took notice the Valves in the Veins of so many several parts of the body, were so plac’d that they gave free passage to the Blood Towards the Heart, but oppos’d the passage of the Venal blood the Contrary way: He was invited to imagine that so Provident a Cause as Nature had not so Plac’d so many Valves without Design: and no Design seem’d more probable, than That, since the Blood could not well, because of the interposing Valves, be Sent by the Veins to the Limbs; it should be Sent through the Arteries and Return though the Veins, whose Valves did not oppose its course that way. (13)

It is also likely that Harvey was taught by (11) Italian philosopher Cesare Cremonini, a prominent follower of Aristotle. (11,12)

Harvey’s Experiments

Harvey made his discoveries because he ignored the conventional wisdom of these medical text books, (9,10) preferring to make his own observations and form his own conclusions when he dissected animals. (9)

The Circulation as Harvey established it

The blood in the left ventricle is sent into the arteries, round by the smaller veins into the venae cavae, and then to the right ventricle again. (9) In this way, the circulation is complete. (9) Arteries and veins therefore form a complete circuit. (4,9) The circuit starts at the heart and leads (4,9) rapidly (11) back to the heart. (4,9) The blood has come back to where it began its circuit of the body there is no to-and-fro movement of blood in the veins, but a constant flow of blood to the heart. (9)

Heart studies via dissection

Harvey’s research was furthered through the dissection of animals. (5,7) He studied the hearts not only of various fishes, amphibian, reptiles, birds, and mammals, but also those of various other animal species. (7) But most important, he not only compared these, he manipulated them in living as well as dead animals. (7) He isolated parts of the heart; he ligated and divided arteries; he exerted pressure on veins on either side of the valves. (7)

Direction of blood flow

Harvey proposed that blood flowed through the heart in two separate closed loops. (12) One loop, pulmonary circulation, connected the circulatory system to the lungs. (12) The second loop, systemic circulation, causes blood to flow to the vital organs and body tissue. (12) His observations of dissected hearts showed that the valves in the heart allowed blood to flow in only one direction. (7,12) This was observed by another simple experiment. (12) Harvey tied a tight ligature onto the upper arm of a person. (12) This would cut off bloodflow from the arteries and the veins. (12) When this was done, the arm below the ligature was cool and pale, while above the ligature it was warm and swollen. (12) The ligature was loosened slightly, which allowed blood from the arteries to come into the arm, since arteries are deeper in the flesh than the veins. (12) When this was done, the opposite effect was seen in the lower arm. (12) It was now warm and swollen. (12) The veins were also more visible, since now they were full of blood. (12) Harvey then noticed little bumps in the veins, which he realized were the valves of the veins, discovered by his teacher, Hieronymus Fabricius. (12) Harvey tried to push blood in the vein down the arm, but to no avail. (12) When he tried to push it up the arm, it moved quite easily. (12) The same effect was seen in other veins of the body, except the veins in the neck. (12) Those veins were different from the others—they did not allow blood to flow up, but only down. (12) This led Harvey to believe that the veins allowed blood to flow to the heart, and the valves maintained the one way flow. (12)

Does Blood pass from one ventricle to the other?

Galen believed that blood was forced from one ventricle to the other. (7) This opinion was to survive, essentially unquestioned, for the next 1,400 years despite the fact that some had denied, and no one had been able to confirm, the presence of holes in the interventricular septum (see below). (13) Harvey was well trained in anatomy, and he, like his idols Versalius and Fabricius, was convinced that the interventricular septum was not leaky to blood. (13) Dissection of the septum of the heart showed that it contained no gaps or perforations, (7) showing that there are no vessels in the heart’s septum: all of the blood in the right ventricle goes to the lungs and then through the pulmonary veins to the left ventricle. (9) Direct observation of the heartbeat of living animals showed that the ventricles contracted together, dispelling Galen’s view. (7)

Does the heart expel or suck in blood?

The prevailing theory of his day was that blood flow was caused by a sucking action of the heart and liver. (12) Most physicians of the time believed that blood entered (4) the lungs which were responsible for moving the blood around throughout the body (7) [OR] the heart where it was heated before it shot out into the veins, not the arteries. (4) [OR] Prior to Harvey, it was thought that the active phase of the heartbeat, when the muscles contract, was when the heart increased its internal volume. (11) So the active motion of the heart was to draw blood into itself. (11) This is why Shakespeare and people like that talk about the blood “coursing through their veins” instead of their arteries. (4) He showed that the heart, not the liver, (9,10) [OR] the lungs (7) is the source of blood movement, (9,10) via its regular contractions. (9,10) pumping it into the arteries (4,9) He showed the world that the heart formed the centre of blood circulation. (9,10) It contracts at the same time as a pulse is felt. (9) The ventricles squeeze blood into the aorta and pulmonary artery the pulse is not produced by the arteries pulling blood in, but by blood being pushed by the heart into the arteries, enlarging them. (9) Harvey investigated the nature of the heartbeat. (11) He observed the heart beating in many animals—particularly in cold-blooded animals and in animals near death, because their heartbeats were slow. (11) When Harvey removed the beating heart from a living animal, it continued to beat, thus acting as a pump, not a sucking organ. (7,12) He concluded that the active phase of the heartbeat, when the muscles contract, is when the heart decreases its internal volume and that blood is expelled with considerable force from the heart. (11) It was important that Harvey saw the heart as a pump, but he saw it as an organic pump, rather than as a mechanical pump. (11) These important theories of Harvey represent significant contributions to the understanding of the mechanisms of circulation. (12)

Does the Liver make blood?

At this time, common thought was that the blood was (12) continually formed anew (7,12) from the digested (7) food (4,7) in the liver. (4,12) It was consumed by the body in the periphery at the same rate that it was produced (7,11) not constantly recycled. (11,12) This was all carried out by the right ventricle and great veins, (7) but the failure to eat obviously did not lead to a depletion of blood volume. (13) Harvey used mathematical data to prove that the blood was not being consumed. (7) He did an experiment to see how much blood would pass through the heart each day. (11,12) He measured the volume of the left ventricle (7,11) how much blood is expelled each pump of the heart, (11,12) and the number of beats per minute made by the heart (11,12) in half an hour: (12) (it was 1000) (12) Every time the heart pumps, 1/8 of the blood in the heart is expelled. (12) He showed that the heart pumped 0.5–1 litre of blood per minute, and the human body contains about 5 litres of blood. (11) All of these estimates were purposefully low, so that people could see the vast amount of blood Galen’s theory required the liver to produce. (12) He was able to show, even with conservative estimates, that more blood passed through the heart than could possibly be accounted for based on the then current understanding of blood flow. (7,11) The amount of passing was much greater than the amount contained in the whole body: (7,11) the liver would have to produce 540 pounds of blood in a day, which was impossible (12) and therefore, the blood had to circulate. (11)

Two blood systems?

It is in the lungs that the transformation of venous blood to arterial blood takes place. (10) Harvey took the foundation of Fabricius’s teaching, and went on to solve the riddle of what (5) part the valves played in the circulation of blood through the body, (4,5) which is by helping the blood get back to the heart, completing the circuit. (4) However, at the time, the influence of oxygen on blood was not understood. (11) Harvey established, on the contrary, that blood in the arteries and the veins is all of the same origin, not manufactured in different parts of the body. (9) The blood on the right side, although carrying air, is still blood. (9)

Did the heart heat the blood?

The ancients thought that the primary function of the heart was the production of heat. (7) Through a meticulous study of what you might call the plumbing of the chest Harvey came to the conclusion that the heart didn’t heat the blood, (4)

Quantitative method?

Harvey based most of his conclusions on careful observations recorded during vivisections made of various animals during controlled experiments, being the first person to study biology quantitatively. (12) This was the first use of quantitative methods to establish verifiability in the natural sciences. (6) [OR] It is tempting to view Harvey, with his quantitative experiment and his model of the heart as a pump, as someone who supported or was inspired by the new mathematical and mechanical ideas of the 17th century, which played significant roles in the scientific revolution of the time. (11) However, there is a need for considerable caution here. (11) Harvey did quantify blood flow, but his quantification is very approximate, and he deliberately used underestimates to further his case. (11) This is very different from the precise quantification leading to the mathematical laws of someone like Galileo. (11)

De Motu Cordis 1628

His work on the circulation of blood (1,3) was described in a book (5) [OR] an exquisitely written 70-page monograph (13) called ‘Exercitatio anatomica (3,5) de motu cordis (2,3) et sanguinis in animalibus’ (3,5) [OR] ‘De Motu Cordis et Sanguinis’ (8) commonly referred to as “de Motu Cordis”. (7) The Latin means ‘An Anatomical Exercise on the Motion of the Heart and Blood in (1,3) Living Beings [OR] Animals’ (1) [OR] An anatomical Account of the Circulation of the Heart and Blood. (2) He dedicated it to King Charles I (3) in terms which underline his royalism:

Most serene King! The animal’s heart is the basis of its life, its chief member, the sun of its microcosm; on the heart all its activity depends, from the heart all its liveliness and strength arise. Equally is the king the basis of his kingdoms, the sun of his microcosm, the heart of the state; from him all power arises and all grace stems. (11)

In the book, he explained how the heart propelled the blood in a circular course through the body. (5,6) The book was published in Frankfurt (6,7) in 1628 (1,2) when Harvey was 50 years old. (7) It was the first complete, detailed (2) and documented (1,5) description (2,5) of the systemic circulation and properties of (2) blood being pumped to the brain and body by the heart, (2,5) It demonstrated the circulation of blood in animals, thus giving a firm foundation for the scientific development of the health professions. (6) He showed that the heart’s beat produces a constant circulation of blood through the whole body. (9) Harvey’s discovery (3) replaced centuries of theory (2,3) with evidence based on experiment. (3) The book was a landmark in the history of science. (6) It must have been composed at different times, for the introduction is more vigorous, and in its critical attitude more youthful, than any of the rest of the 17 chapters. (6)


De Motu Cordis’ brought Harvey both fame and criticism. (8) Harvey finally put to rest some of the errors Galen had made so many years earlier. (9) It confronted the prevailing paradigm of Galen, which dominated thought of the time, and was of significant importance in overcoming that pernicious influence. (12) You might think that he would have been inundated with patients afterwards, (4) but in fact his work was not immediately popular. (3,4) At one point Galen had had to flee from Rome because his methods threatened the careers of Rome’s quack physicians. (9) Ironically, in correcting Galen’s mistakes about blood and circulation, Harvey himself ran into trouble with Europe’s latest crop of quack physicians. (9) Many found it hard to accept Harvey’s ideas (3,6) which contradicted the theories behind bloodletting (3,9) derived from Galen, (6,9) which, though worthless, (9) were central to medical practice of the time. (3) It was attacked by distinguished members of the academic community, often on the sole grounds that it dared to question Galen and the normal science, so strong was the grip of the authority of antiquity on men’s minds. (13) Some doctors affirmed they would “rather err with Galen than proclaim the truth with Harvey”. (14) Harvey was aware that his ideas would damage the interests of many doctors of the day and cause him difficulties, (6) and indeed his practice suffered severely, because of his radical views. (4,6) He was right to be worried: in those days doctors were very conservative and wouldn’t make innovations, which were associated with quacks. (4) Good doctors, it was thought, dispensed medicine and diagnosed purely in accordance with the way the ancients had taught. (4) Such a major shift in thinking about the body needed to be very well supported by experiment and argument to avoid immediate ridicule and dismissal; hence the delay before the publication of his central work. (11) This may explain why Harvey had his book published abroad (6) and in Latin. (7) It appeared as a poorly printed 72-page book, done by an obscure (6) German (6,7) printer. (6) Galen had not got everything wrong. (9) Some of his teachings were useful. (9) While not forced to flee for his life, Harvey’s own medical practice declined because of the barrage of criticism he took from physicians. (9) The greatest medical discovery of all time caused a considerable amount of financial distress to its discoverer! (4) He later referred to ‘the storm my previous research caused’. (9) [OR] His discovery was received with great interest in England. (5)

European Tours

On the continent, (5) Leyden University (Leiden University) was the first to accept Harvey’s views on the continent, but (12) he was greeted with some scepticism, and (5,12) it took half a century (12,13) before it was accepted by as distinguished a center of learning as the University of Paris. (13) Harvey visited Italy in 1531: he was appalled by the effects of the Thirty years’ War:

It is scarce credible in so rich, populous, and plentiful countries as these were that so much misery and desolation, poverty and famine should in so short a time be, as we have seen. It will be a great motive for all here to have and procure assurance of settled peace. It is time to leave fighting when there is nothing to eat, nothing to be kept, and nothing to be gotten”. (14)

He returned in 1632. (14) In 1636, Harvey returned to Italy. (10,11) He was invited by the Jesuits at the English College, Rome. (10,14) During the diplomatic mission of 1636 he visited Italy to look for paintings for the royal collection, (11) and enjoyed the rich artistic heritage that the country displayed while he was in Italy. (10) It is possible he met Galileo in Florence en route. (14) The same year, he acted as doctor to a diplomatic mission sent to see the Holy Roman emperor, Ferdinand II. (11) This involved nearly a year of travel around Europe. (11) He met renowned German professor of medicine Casper Hofmann at Nürnberg and attempted to demonstrate the circulation of the blood to him. (11) Apart from medicine, Harvey was interested in philosophy, literature, and art. (10,11)

Relationship with eminent persons

He was friends with Robert Fludd, (11) a colleague at the College of Physicians (12) and important English physician and philosopher whose primary interest concerned natural magic, and Thomas Hobbes, a famous political philosopher. (11) Fludd, was the first to accept Harvey’s circulatory model. (12) He was also acquainted with John Aubrey, the 17th-century biographer, who gave an account of Harvey in his manuscript Brief Lives. (11) He influenced René Descartes, (2) who also accepted the discovery of the circulation of the blood [OR] he was deeply and bitterly opposed to the mechanical philosophy of French mathematician and philosopher René Descartes as well as to any purely mechanical conception of the human body. (11) Harvey disagreed with Descartes about the beating of the heart, and said that spirit was an inherent and material component of the blood (Gugliani 2004). (12) Descartes disagreed with Harvey’s explanation for the movement of the heart (Giglioni 2004). (12)

Civil War 1642-6

Harvey was a committed royalist. (6,11) He followed the king on the Scottish campaigns of 1639, 1640, and 1641, and (11) retained a close relationship with the royal family through the English Civil War. (5,11) When King Charles I went to Oxford (6,10) in 1642, (6,12) Harvey accompanied him (6,10) and stayed there, (12) being made doctor of physic at Oxford (6,10) in 1642 (10) One of the worst setbacks Harvey experienced concerned the loss of a great deal of written work when parliamentary troops ransacked his house in Whitehall in 1642, (11,12) during the riots at the start of the First English Civil War. (12) He lost all of his notes on the generation of insects (Gugliani 2004). (12) He considered the loss of his book on (11,12) natural history and (12) the generation of insects, (11,12) which contained the results of a great amount of research, to be the “greatest crucifying” that he had in his life. (11) He also lost notes on patients, postmortem examinations, and animal dissections. (11) Harvey himself went with the king on campaign. (12) He witnessed the Battle of Edgehill, (5,11) the first pitched battle of the English Civil War, (12) and protected the king’s children while it was taking place, (10,12) hiding them in a hedge. (12) He was forced by enemy fire to shelter behind the Royalist lines and at the end of the battle he tended to the dying and wounded. (12) During the rest of the War, he served as a physician, and tended the wounded on various occasions. (10) After traveling with King Charles to Oxford, , discontinuing his work with St Bartholemew’s Hospital in 1643, when he took the position of Warden (head of house) of Merton College (Gugliani 2004). (12) In 1643 Harvey ceased to work at St Bartholomew’s Hospital. (6,11) This was because (6,11) he retired when his brothers died, [OR] the parliamentary authorities in London had him removed because he was a Royalist. (11) Thanks to Charles I he was, for a short time, (5) warden of Merton College, Oxford (1645 (5,10) – 1646). (5) The surrender of Oxford in 1645 marked the beginning of Harvey’s retirement from public life as well. (10) In 1646 he fled with the court from Oxford and (6) attended the King in Newcastle when he was held in captivity. (11) He eventually returned to London to live with his remaining brothers (6,10) in 1647 (11) having lost his wife. (10)

Post War: Microcosm/Macrocosm and Renaissance/Science

Harvey’s work was attacked, notably by Jean Riolan in Opuscula anatomica (1649). (12) This forced Harvey to defend himself (12) in 1649, in his ‘Exercitationes Anatomicae Duae (11,12) [OR] Duae Anatomicae (11) de Circulatione Sanguinis’ (11,12) ad Joannem Riolanem, Filium, Parisiensem (11) (Two anatomical exercitations on the circulation of the blood), (11,12) known in short form as De Circulatione, (12) in which he distanced himself from the explanation of the heartbeat given (11,12) by Rene Descartes. (12) [OR] by French anatomist Jean Riolan. (11,12) He argued that Riolan’s position was contrary to all observational evidence. (12) Harvey was very much influenced by the ideas of Greek philosopher Aristotle and the natural magic tradition of the Renaissance. (11) His key analogy for the circulation of the blood was a macrocosm/microcosm analogy with the weather system. (11) A macrocosm/microcosm analogy sees similarities between a small system and a large system. (11) Thus, one might say that the solar system is a macrocosm and the atom is a microcosm. (11) The Renaissance natural magic tradition was very keen on the idea of the human body as a microcosm. (11) The macrocosm for Harvey was the Earth’s weather cycle. (11) Water was changed into vapour by the action of the Sun, and the vapour rose, was cooled, and fell again as rain. (11) The microcosm was the human body, where the action of the heart was supposed to heat and change the blood, which was cooled again in the extremities of the body. (11) Harvey says (and compare the earlier quote concerning the king) that:

So the heart is the beginning of life, the Sun of the Microcosm, as proportionably the Sun deserves to be call’d the heart of the world, by whose vertue, and pulsation, the blood is mov’d, perfected, made vegetable, and is defended from corruption and mattering; and this familiar household-god doth his duty to the whole body, by nourishing, cherishing, and vegetating, being the foundation of life, and author of all. (11)

This was critical to Harvey. (11) How could arterial blood be rapidly, efficiently, and consistently converted into venous blood (and vice versa) within one system? This was a key question, which prompted Harvey to draw on his macrocosm/microcosm analogy. (11) It also should be noted that much of his terminology for change was drawn from the alchemy of his time. (11) Harvey was very much a man of the later Renaissance—not a man of the scientific revolution and its mechanical nature. (11)


He retired from St Bartholomew Hospital and other official duties including his royal duty as well. (10) [OR] He attended the King in Newcastle when he was held in captivity. (11) He now took great interest in the science of reproduction, (8,11) most likely derived from his master Fabricius, and made significant contributions to embryology. (8) During his lectures on anatomy, Harvey made comments on animal genitalia, on different kinds of fœtuses, and on the development of the chick. (8) He compared oviparous and viviparous animals. (11,12) He worked on chickens as an example of oviparous reproduction, in which embryonic development occurs within eggs hatched outside the mother’s body, and on deer as an example of viviparous reproduction, in which embryonic development occurs within the mother’s body, resulting in the birth of live young. (11) At the time, reproduction was poorly understood, and Harvey investigated issues of the role of sperm and menstrual blood in the formation of the embryo. (11) He was the first to suggest that humans and other mammals reproduced via the fertilisation of an egg by sperm. (5,10) [OR] Harvey, however, did not understand the process of fertilization of the egg with semen (Gugliani 2004). (12) He collected notes over several years on his observations on reproduction and embryology, resulting in the publication of his final work, which explored the generation of animals. (8) Harvey was reluctant to publish this work because of ‘the storm my previous research caused’. (9) It was George Ent, Harvey’s fellow physician and long-time friend, who persuaded him to publish the work. (8) Ent visited Harvey in the winter of 1648 because he believed that Harvey had other work worthy of publication, hidden in secret. (8) Harvey said: ‘It is better to grow wise in private at home, than to publish what you have amassed with infinite labour, to stir up storms that may rob you of peace and quiet for the rest of your days.’ (9) Harvey’s perfectionist attitude made him reluctant to reveal his work until his discussion on the “Generation of Insects” was complete5, but after much discussion, he granted Ent control of the book’s future. (8)

De Generatione animalium

Harvey agreed to give Ent the draft of (8) a second masterpiece, which concentrated on embryology (10) called ‘Exercitationes (8) ‘De Generatione Animalium’ (6,8) ‘On the Generation of Animals’. (6) Ent had it published in London in March (8) 1651 (6,8) de Generatione Animalium’ (6,8) It pioneered modern embryology (6,8) and comparative sex psychology. (6) In this book he established several theories that would set the stage for modern embryology and addressed many embryological issues including conception, embryogenesis, and spontaneous generation. (8) Exercitationes was divided into seventy-two chapters on topics in development, and three additional chapters covering parturition, the structure of the uterus, and conception. (8) The first thirteen chapters describe the comparative anatomy of the reproductive organs of various animals. (8) Chapters 12 to 25 demonstrate the day-by-day development of a chick in the egg. (8) In his observations, Harvey discovered the cicatricula, the area of the embryo that contains all the embryonic cells and from where generation proceeds. (8) In chapters 26 to 62 he discusses at length theories and errors of generation, criticizing some of Aristotle’s and Galen’s conclusions as erroneous and hasty. (8) Harvey also established several of his own conclusions about theories of generation. (8) First, he denounced spontaneous generation by claiming that even maggots and worms have some origin in eggs. (8) This example is also associated with the establishment of the doctrine ex ovo omnia, meaning that all life originates from an egg, a doctrine that Harvey helped advance. (8)


Moreover, in chapter 51, (8) Harvey expressed support for the theory of epigenesis, (6,8) which stated that the organism does not exist as a minute entity within the ovum but develops from it by a gradual building up of its parts. (6,10) rather than preformation, through his description of the formation of limbs. (6,8) Last, he rejected the Aristotelian and Galenic theories about early embryogenesis. (8) Aristotle believed that embryos form from the combination of menstrual blood and semen, while Galen believed it was female semen and male semen. (8) In addition to providing new information about conception and early human development Harvey also criticized many of his predecessors, particularly his old master Fabricius. (8)

Microscopic validation of Harvey’s view

Harvey’s work in this area generated a wealth of observational detail. (11) His observations were excellent, (11) but such matters could not be resolved properly without the use of the microscope. (6,11) Harvey was working just before the invention of the microscope (4,6) It took a further two centuries before (5,10) a mammalian egg was finally observed, (5) confirming Harvey’s idea in the 19th century, (10) but nonetheless Harvey’s theory won credibility during his lifetime. (5)

Later Life


In 1651, (9,12) aged 73, (9) Harvey donated money (9,12) anonymously (9) to Merton College (12) [OR] the College of Physicians (6,9) for building and furnishing a library, which was dedicated in 1654. (12) The identity of the donor became known and the College built a statue in Harvey’s honour, (9) although he refused its presidency. (6) In 1656, he gave an endowment to pay a librarian and to present a yearly oration, which continues to the present day in his honour. (12) He suffered from gout, kidney stones and insomnia in his later life. (10) In 1651, he unsuccessfully attempted to take his life with laudanum. (10)

De Motu in English

Harvey was still regarded as an excellent doctor, (12) but in 1653 (6,11) [OR] 16586 (7) the first English edition of De motu cordis appeared, (6) and Harvey’s genius was fully recognized. (6,9) He received the support of the Royal College of Physicians, (3) and the majority of respectable anatomists saw the truth of Harvey’s work within his lifetime. (9,12)


Harvey lived during the European witch hunt. (11) He was involved in one of the cases, in 1634, (11) and had to examine four women accused of witchcraft. (6,11) Harvey was a prominent sceptic regarding allegations of witchcraft. (14) [OR] At a time when belief in witches was commonplace and to deny their existence was heresy, it would have been very easy to interpret any suspicious behaviour or mark on the body as positive evidence of witchcraft. (11) It is much to Harvey’s credit that he treated the case with an open mind and was willing to consider scientific explanations of the evidence allegedly showing witchcraft. (11) The alleged witches were found to be innocent. (6,11) He performed a postmortem examination on Thomas Parr, reputed to have lived 152 years. (6)

Limitations of his work

Harvey was working just before the microscope (4,6) so though he understood that the heart pumped blood into the circulatory system, he had no knowledge of the influence of oxygen in the blood (1) nor knowledge of the existence of capillaries. (1,11) Without a microscope he could neither demonstrate directly how blood would move from arteries to veins, although he postulated the capillary anastomoses, nor could he see directly how the embryo gradually aggregated. (6) He therefore didn’t know how the blood got from the arteries to the veins but he made a very bold guess that this was done by tiny vessels so small he couldn’t see them. (4,6) He was perfectly right of course and we call them capillaries. (4,7) The demonstration of the existence of small capillary (7,11) anastomoses, (6,7) vessels (11) between arteries and veins, (7,11) was completed in 1661 by Marcello Malpighi, (6,7) the great Italian biologist, who was one of the first to have and use a microscope, (6,11) and saw the capillaries while studying the lungs of frogs. (13)


He died of a stroke (6,12) [OR] a cerebral haemorrhage (9,10) on 3rd June 1657, (2,5) aged 79, (2,7) at the home of one of his brothers (9,10) in Roehampton, (2,10) London (2,8) and, “lapt in lead”, (6,10) was buried in St Andrews (12) church, (6,12) in the village of (9) Hempstead (6,9) in the English county of Essex. (9,10) He had no children, (9) and his wife Elizabeth died before he did. (9,10) Nine years after his death some of his writings were lost when the Great Fire of London in 1666 engulfed the Royal College of Physicians’ library. (11) He left money in his will for the founding of a boys’ school in his native town of Folkestone; opened in 1674, the Harvey Grammar School has operated continuously up to the present day. (12)

Impact on Modern Medicine

By 1700, Hermann Boerhaave, the great Dutch teacher of medicine in Leyden, stated that nothing written before Harvey was any longer worthy of consideration (Booth 2001). (12) Galen’s theory was patently groundless to any thinking, critical mind. (13) Nevertheless, Harvey’s work (9,12) was opposed by conservative physicians (11) and had little effect on general medical practice at his time—blood letting, based on the prevailing Galenic tradition, was a popular practice, and continued to be so even after Harvey’s ideas were accepted: (9,12) it probably shortened the life of Ada Lovelace in the 1830s. (9) His work did much to encourage others to investigate the questions raised by his research, and to revive the Muslim tradition of scientific medicine expressed by Nafis, Ibn Sina (Avicenna), and Rhazes. (12) Harvey was the founder of modern experimental physiology and the first to use quantitative methods to establish verifiability in the natural sciences. (6) His work on the circulation of blood (3,10) opened new avenues of study in blood circulation and distribution, (10) and is fundamental to modern understanding of the role of the heart in the body. (3,4) It was a discovery of colossal importance. (4) There have been numerous advances since but I’d suggest that circulation was so crucial because without it the others wouldn’t have emerged. (4) You couldn’t undertake modern surgery or give an injection without circulation and can you imagine any modern medical discovery without the knowledge of the blood pumping from the heart? (4) Though his work in embryology was overshadowed by his work on the circulatory system, Harvey also provided a basis for the development of modern embryology. (8) Joseph Needham, author of A History of Embryology, summarized Harvey’s view from De Generatione, emphasizing Harvey’s advancement of the doctrine ex ovo omnia, the discovery of the cicatricula as the origin of the embryo, denial of spontaneous generation, and the dismissal of Aristotelian and Epicurean theories of embryogeny. (8) On St Luke’s Day, October 18th 1883, his remains were reinterred, the leaden case carried from the vault by eight Fellows of the College of Physicians, and deposited in a sarcophagus. (10) To commemorate his contribution to the field of anatomy and physiology, (10) the William Harvey Hospital was constructed in the town of Ashford, several miles from his birthplace of Folkestone in 1973. (2,10) Arthur Schlesinger included William Harvey in a list of “The Ten Most Influential People of the Second Millennium” in the World Almanac & Book of Facts (Schlesinger 2000). (12)


  1. https://www.biography.com/people/william-harvey-9330709
  2. https://en.wikipedia.org/wiki/William_Harvey
  3. http://broughttolife.sciencemuseum.org.uk/broughttolife/people/williamharvey
  4. https://www.historyextra.com/period/stuart/william-harvey-reveals-the-circulation-of-the-blood/ http://www.bbc.co.uk/history/historic_figures/harvey_william.shtml
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776239/
  6. https://embryo.asu.edu/pages/william-harvey-1578-1657
  7. https://www.famousscientists.org/william-harvey/
  8. https://www.thefamouspeople.com/profiles/william-harvey-492.php
  9. https://www.britannica.com/biography/William-Harvey
  10. http://www.newworldencyclopedia.org/entry/William_Harvey
  11. https://www.physiology.org/doi/full/10.1152/nips.01391.2002
  12. https://en.wikipedia.org/wiki/William_Harvey


10 (New World Encyclopaedia) looks very close to 11 (Physiology.org)

Appendix I: the Discovery

Harvey, observing the motion of the heart in living animals, was able to see that systole was the active phase of the heart’s movement, pumping out the blood by its muscular contraction. Having perceived that the quantity of blood issuing from the heart in any given time was too much to be absorbed by the tissues, he was able to show that the valves in the veins permit the blood to flow only in the direction of the heart and to prove that the blood circulated around the body and returned to the heart. Fabricius, his teacher in Padua, had discovered the valves in the veins. In Chapter 8 of “De Motu cordis”, Harvey wrote how he hypothesized that the blood circulates: “In truth, when, from a variety of investigators through dissection of the living in order to experiment and through the opening of arteries, from the symmetry and magnitude of the ventricles of the heart and of the vessels entering and leaving (since Nature, who does nothing in vain, would not have needlessly given these vessels such relatively large size), from the skilful and careful craftsmanship of the valves and fibres and the rest of the fabric of the heart, and from many other things, I had very often and seriously though about, and had long turned over in my mind, how great an amount there was, that is to say how great the amount of transmitted blood would be [and] in how short a time that transmission would be effected. … I began privately to think that it might rather have a certain movement, as it were, in a circle … It has been shown by reason and experiment that blood by the beat of the ventricles flows through the lungs and heart and is pumped to the whole body. There it passes through pores in the flesh into the veins through which it returns from the periphery everywhere to the centre, from the smaller veins into the larger ones, finally coming to the vena cava and right atrium. This occurs in such an amount, with such an outflow through the arteries and such a reflux through the veins, that it cannot be supplied by the food consumed. It is also much more than is needed for nutrition. It must therefore be concluded that the blood in the animal body moves around in a circle continuously and that the action or function of the heart is to accomplish this by pumping. This is only reason for the motion and beat of the heart.” (7)


F England and Italy;

R Previous ideas of blood and organs; Aristotle; Galen; Fabricius; conservatism of doctors. Circulation of Blood; Embryology; Royalist; Edgehill; epigenesis; Loss of documents and St Barts’ job

E Family background prosperous; lost money by losing patients; left money and property to RCS.

S Merchant or farmer; link to royal family; Formal education; book printed;

C Royalist; jurat;

I Fabricius and Galileo at Padua; sending book to Frankfurt; James I hypochondriac

P Controversy over his ideas;

L Use of Latin as universal European Language and to hide his ideas from critics.


C Vesalius; royal patronage; Fabricius.

T After Vesalius, Copernicus; Galileo; Bruno.


P Padua

Near Venice; top medical university

A Al Nafis and Servetus

Ideas of circulation before Harvey; little impact

S Scholarship Boy

NB Renaissance: giving financial value to knowledge

S Science But Not Quantitative

Still with one foot in religious explanation. Not like Galileo or Descartes

E Empirical Verification and Epigenesis

But he did learn from the evidence of experiments.

D De Motu Cordis ; De Generatione Animalium

Book published 10 years after lecture on it – fear of medical establishment justified.

H Heart pumps too much blood

For it to have been made out of food and used up

A Angry Doctors continue Bloodletting

Better Galen wrong than Harvey right – still used 200 yrs later

R Royal Deer Dissected

Many aspects of circulation did not require human subjects.

M Microscope missing (guessed capillaries)

Seen 4 years after his death by Malpighi

F Fabricius and the Valves

F had seen them but not explained their function correctly.

U Upper Class Patrons

Almost essential – see Vesalius and Paré also.

L Lumley Lectures and Latin

On the edge of the medical establishment

1 In 1313, King Edward II granted the Town a Charter of Incorporation, by which it could elect a Mayor, bailiff and 12 jurats. http://www.folkestonetc.kentparishes.gov.uk

2 So at the age of 20, which means he can’t have gone to Padua when he was 20.

3 Obviously ‘William’!

4 ‘The Restoration of Christianity’, a Renaissance, pre-Scientific, view.

5 This was a re-write of the work destroyed by parliamentarian soldiers in 1642

6first English translation did not appear until two decades later’ than the 1628 original.


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