Upon leaving the carnivorous man-eating island, Pi says, "I preferred to set off and perish in search of my own kind than to live a lonely half-life of physical comfort and spiritual death on this murderous island." What does Pi mean by "spiritual death"?

Upon leaving the carnivorous man-eating island, Pi says, "I preferred to set off and perish in search of my own kind than to live a lonely half-life of physical comfort and spiritual death on this murderous island." What does Pi mean by "spiritual death"? How could that type of death be seen as worse than physical death?