William Harvey: Blood Circulation

William Harvey (1578-1657) was an influential doctor whose main contributions came through his work in the circulatory system of the body. In this post, we will take a brief look at his life.

Life as a Student

William Harvey was an English man who decided as a young man that he wanted to be a doctor. This desire led him to Padua, Italy, where he studied medicine. During Harvey’s studies, Galileo was also a teacher at the same university. Some of Galileo’s views towards science would have a strong influence on Harvey.

For example, Galileo insisted that experiments were the way to learn about anything. This was during a time when people would blindly obey authority in many matters. The authority of the past was not the final answer. People needed to explore for themselves. Harvey applied these ideas that Galileo had in the non-living science in the medical sciences.

During his studies, Harvey read all the works of the great physicians of the past, such as Hippocrates, Galen, and most recently, Vesalius. Vesalius mentions Galen’s mistakes, yet doctors still clung to Galen in matters that had not been questioned.

Some of the errors that doctors clung to include the ideas that veins carried blood away from the heart, the liver made blood, blood ebbed and flowed like the ocean in the body, and that the blood caused the heart to beat. This was all based on speculation rather than observation through experiments.

As a student, Harvey attended many dissections. During these demonstrations, he was allowed to see the veins, arteries, and heart. Inside the veins are little trap doors that help with the flow of blood. However, Harvey noticed that these doors were on the wrong side if blood was supposed to flow to the heart.

Life as a Doctor

After finishing medical school, Harvey did several experiments involving blood circulation. In these experiments, he would tie off veins and arteries in the body. His conclusion from this was that veins carried blood to the heart, and arteries carried blood away from the heart. In addition, Harvey concluded that blood was reused and not created by the liver.

When Harvey shared his results, not too many people seemed to care. People did not see how this knowledge would help with the prevention of disease. Doctors at this time did not know that understanding circulation was the key to many forms of disease. Harvey demonstrated this when he tied off the arteries to a tumor on a person. With the loss of blood, the tumor withered away.

One question Harvey was never able to answer was how blood flowed from arteries to veins. This question was answered a few years before Harvey’s death thanks to the use of a microscope that discovered tiny blood vessels called capillaries.

During his life, Harvey was often attacked by other doctors for his discoveries. These critics were never able to prove that Harvey was wrong; instead, they quoted Galen as the final word. Despite this, Harvey became the King of England’s physician and was elected president of the College of Physicians even though he turned this down.


Curiosity may be one of the most essential traits of innovation. Authority is not wrong; however, it can be abused and lead to people sacrificing their responsibility to think for themselves. Harvey was an individual who decided he would see for himself if what others said was true.

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