greek philosopher and scientist aristotle (384 - 322 bce) followed hippocrates and proposed that the heart had three ventricles, rather than two, that all connected to the lungs. the greek physician erasistratus (315 - 240 bce) agreed with hippocrates and aristotle that the heart was the origin of all of the vessels in the body but proposed a system in which air was breathed into the lungs and traveled to the left ventricle via pulmonary veins. it was transformed there into the pneuma and distributed throughout the body by arteries, which contained only air. in this system, veins distributed blood throughout the body, and this blood did not circulate, but rather was consumed by the organs.