Renee Laennec
Doctor
French physician who rose to fame for inventing the stethoscope.
At age 12, he started studying under the direction of his uncle, who was a medical professor.
One day, while tending to an overweight patient whose heartbeat couldn't be heard or felt, he devised a tool to amplify the heartbeat sound.
His father discouraged him from working as a doctor, and for a while he was more interested in philosophy and art.
William Harvey, who lived about two centuries before Laennec, was another great contributor to medical science.