In human perception, the heart was not always part of the blood circulating system. It was later included as a suction pump until Harvey argued that the heart is actually a compression pump, the central organ of the circulation, and the only organ responsible for the motion of blood. Considered initially as an autonomous pump, the heart gradually became viewed as subservient to the needs of the peripheral organs it perfuses. Constant properties assigned to the heart had to be replaced, one after another, by adjustable parameters. Even the adequacy of the heart as the sole pump has been doubted, an issue that resurfaces today.