[Pulmonary circulation in the history of medicine]

The history of medicine is frequently equivocal, fanciful and contradictory because of the interlacing with philosophy, theology and astronomy. However, old achievements, that were completely forgotten, are frequently rediscovered and hailed as new. Although widely dispersed in the centuries, we believe that a continual progress in the knowledge of pulmonary circulation is present in the works of the ancient scientists. For instance, Galen's statements that heart and lung act together and that they contribute to the preservation of body heat may anticipate the modern ideas of the metabolism and of heart-lung unit.