The phrenic nerves control the diaphragm, our major muscle of respiration (breathing). From the Greek, phrenic means both diaphragm and mind. The ancient Greeks believed that the diaphragm was the seat of our emotions. Sound farfetched? Have you ever “heaved a sigh” of sadness or relief? The same stem is found in schizophrenic and, less obviously, in frenetic, meaning extremely agitated or maniacal. The latter word underwent a transformation from the Greek word phrenitikos. The ancient Romans had a related word in the Latin, mentum, which means both mind and chin! Maybe, not so farfetched, hmmm? Ever rub your chin while thinking? Perhaps the ancients thought massaging our chin stimulated thought. Are you familiar with Rodin’s statue of The Thinker, the sitting man with his chin resting on his hand? Conjure up a “mental” image!