For 1,400 years anatomists kept finding holes in the heart that weren't there
Galen's theory needed tiny openings between the heart's two ventricles, and generation after generation of anatomists dutifully reported seeing them. Andreas Vesalius simply admitted he could not. When he kept contradicting the ancient master, his old teacher offered a remarkable defence: perhaps the human body itself had changed since Galen's day.
Vesalius was born Andries van Wesel in Brussels on 31 December 1514, into a family of court medicine; his grandfather had been physician to Emperor Maximilian. He studied in Leuven and then Paris, where he learned Galen's theories and haunted the charnel houses of the Cemetery of the Innocents to examine bones. War between France and the Empire drove him home in 1536, and on the very day he graduated he was offered the chair of surgery and anatomy at Padua.
He changed how the subject was taught. Lecturers had traditionally read Galen aloud while a barber-surgeon cut up an animal, and nobody checked whether the text matched. Vesalius dissected with his own hands and pressed students to do likewise, trusting only direct observation. In Bologna he realised Galen had worked on animals, chiefly Barbary macaques, since Roman custom barred human dissection. A Padua judge began supplying bodies of executed criminals, and the errors piled up: the human lower jaw is one bone, not two, and people lack a web of vessels at the brain's base found in sheep.
In 1543, aged just 28, he published De humani corporis fabrica in seven books, with 273 illustrations of unprecedented detail, and dedicated it to Charles V. Pirated copies appeared almost at once, as he had predicted. That year he also assembled the skeleton of an executed felon in Basel, now the oldest surviving anatomical preparation, still on show at the university there.
Success brought a post as imperial physician, where academic doctors sneered at him as a mere barber-surgeon, and in 1551 an inquiry in Salamanca examined the religious implications of his methods before clearing him. In 1564 he set off for Jerusalem, likely a pretext to escape royal service; the tale that he fled an Inquisition death sentence is now dismissed. Returning to take up the Padua chair again, he was shipwrecked on Zakynthos and died there at 49, so indebted that a benefactor paid for his funeral.
Source: Andreas Vesalius
