The Bible speaks of hearts of stone and flesh:
Ezekiel 36:26 (NIV)
I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh.
Your heart pumps life-sustaining blood to every cell in your body. The stonier your heart, the weaker the pump, the less life to the cells. You starve, cell by cell.