This study provides an integrated analysis of θυμός (thymós). A psychosomatic concept, found in Greek epics and medicine, θυμός designates courage as a “vital force around the chest”. Later, its meaning has been specified in two fields: 1) θυμός, thymós (philosophy), the irascible soul (θυμοειδές, thymoeides), parallel to the concupiscible soul and opposite to the rational one, according to Plato’s tripartition; 2) θύμος, thymus (anatomy), a cardiac gland of the vascular system. Today, the idea that θυμός, courage, and θύμος, cardiac gland, could have a common semantic root – θύειν (thyein) “to sacrifice by blowing and burning” – seems almost impossible. Our aim is to reconstitute the concept of θυμός, demonstrating how it has been reduced ...