In spite of all the enforced physical and mental primitiveness of the life in a concentration camp, it was possible for spiritual life to deepen. Sensitive people who were used to a rich intellectual life may have suffered much pain (they were often of a delicate constitution), but the damage to their inner selves was less. They were able to retreat from their terrible surroundings to a life of inner riches and spiritual freedom. Only in this way can one explain the apparent paradox that some prisoners of a less hardy make-up often seemed to survive camp life better than did those of a robust nature.

— Viktor E. Frankl, Man’s Search for Meaning, 1946, Beacon Press (2006 edition), p. 51