The mental reactions of the inmates of a concentration camp must seem more to us than the mere expression of certain physical and sociological conditions. Even though conditions such as lack of sleep, insufficient food and various mental stresses may suggest that the inmates were bound to react in certain ways, in the final analysis it becomes clear that the sort of person the prisoner became was the result of an inner decision, and not the result of camp influences alone. Fundamentally, therefore, any man can, even under such circumstances, decide what shall become of him-mentally and spiritually. He may retain his human dignity even in a concentration camp.
― Viktor Frankl, Man’s Search for Meaning