The stethoscope was invented by a doctor too embarrassed to place his ear on a woman's ample bosom.
Before the invention of the stethoscope, a physician would listen to a patient's heart by placing his ear over the chest.
In 1816, René Laennec, a physician and devout Catholic, was called to examine a young woman suspected to have a diseased heart. According to the medical procedure of the time, Laennec tapped his hand on the patient's back and tried to listen to the resulting sound (the "thumpyness" of the sound was used in diagnosis). Unfortunately, because the patient was too fat, he couldn't hear anything.
Too embarrassed to put his head on the young woman's ample bosom to listen closer, Laennec came up with a simple yet brilliant solution: he rolled a piece of paper into a cylinder and used that to listen to the patient's heartbeat.
Laennec later created a new instrument made from hollow wooden cylinder he called stethoscope, from the Greek words stethos (chest) and skopos (examination).
Now, you would think that such an invention would be universally embraced by the physicians of his time, but you'd be wrong. Even the founder of the American Heart Association, Lewis A. Conner, resisted the stethoscope, preferring to listen to the heart directly over the chest of the patient.