Michael Servetus (1511-1553) has been widely considered to be the discoverer of the lesser circulation (of the blood through the lungs), as he was the author of the first printed description of lung perfusion. His description, however, does not refer to any type of circulation but to pulmonary perfusion. He described the blood as being produced upstream in the liver and consumed downstream by all organs. The ‘copious’ perfusion through the lungs enables the blood to take up the spiritus divinus, the Spirit of God, from the outside air. Servetus particularly wanted to use his description to explain how by breathing in and through the bloodstream the human soul comes into contact with the spirit of God. Because of the perceived blasphemous nature of his books, Calvin intervened and Servetus was burned to death at the stake in Geneva in 1553. Almost all of Servetus’ books were destroyed and were not rediscovered until 150 years later. Therefore, Harvey’s discovery of the circulation of the blood, published in 1628, could not have been influenced by Servetus’ ideas.