The heart, we must not forget, is a mere muscle, which is no more capable of being the seat of an emotion than our biceps or our calves.
The heart is an elaborate centripetal and centrifugal pump which, in obedience to orders or impulses coming from elsewhere, draws the blood out of the veins and sends it into the arteries at a varying rate of speed.
=A Dead Heart Can Be Made to Beat.= The heart, taken out of the body and attached to a well fitted system of pipes, thru which an appropriate fluid is circulating, will start beating anew and keep on beating until decay sets in, due to the fact that the proper nourishment is lacking.
Talking of a sensitive heart, of a tender heart or of a heart of stone means merely juggling with pretty pictures which correspond to nothing physiologically. There may be sensitiveness, tenderness or stony harshness somewhere in the organism and the heart may give them expression by its fluctuating beats, but it acts on such occasions as a mere registering apparatus.
Adrenin taken by the mouth or injected into the blood stream causes the heart pump of a perfect indifferent man to throb as wildly as the heart of a lovelorn swain. Strong doses of the nitrates may cause valvular insufficiency and "break" a heart more effectively than any catastrophe in one's sentimental life.
=The Heart is a Respectable Organ.= The choice of the heart as the organ of the emotions, in particular of the love emotion, is certainly due to the fact that it is such a faithful registering apparatus and also to a "displacement upward" frequently observed in modern civilised thought.
We do not willingly mention the abdomen and therefore have rechristened it the stomach. We have read many times the appalling statement that a woman carries her child "under her heart." The seat of the mind which materialist physicians of ancient Greece located in the intestines, rose later to the level of the solar plexus and with Descartes finally reached the pineal gland. Likewise the part of the body where love cravings receive their physical satisfaction having become taboo, the seat of love has been raised from the pelvis to the thorax, from the primary genital region to the breast, which bears secondary sexual characteristics.