December 22, 2014 4:35 PM EST

In the 17th-century, William Harvey, an English physician, worked to debunk the misconceptions that phlegm and bile were at the root of all health problems.

He was a leading figure in cardiology at the time, and it is to him that we owe the discovery of blood circulation. Almost forgotten now, Harvey was a trailblazer back then, or as the World Science Festival sees it, “he ruffled a lot of feathers, but eventually became a major influence on modern medicine.”

Watch the video above for more on his controversial, and until now overlooked, legacy.

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