Inmates performed hard manual labor, such as digging ditches and tunnels for water mains or laying railway tracks, while working on a near-starvation diet. His observations thus have both the gritty reality of personal experience and the more universal quality of shared suffering. As a psychiatrist, Frankl was primarily interested in recording the mental and emotional reactions of prisoners to their experiences. Three distinct phases of the typical prisoner's reactions are noted: the period of shock following his admission, the period when he was entrenched in camp routine, and the period following his liberation. Each phase has its striking images and typical symptoms. The reader will not soon forget the high-ranking Schutzstaffel (SS) officer who flicks his finger casually to right or left as the incoming prisoners file by. Those directed to the right look capable of hard physical labor; those directed to the left head for the "showers," where they are gassed and shoveled into the insatiable furnaces. This was but the first of many selections between life and death that each prisoner must face. More experienced inmates warned them to shave every day, stand tall, and walk vigorously; even a limp because one's feet were frostbitten might cause an SS guard to wave a prisoner aside and send him to the oven.
The shock and horror of the first phase, marked by prisoners' thoughts of suicide, longing for home and family, and disgust with the ugliness and filth of the surroundings, gave place to the relative apathy of phase 2. Endurance in such circumstances demands a certain callousness. Eventually, the emotions of disgust, horror, and pity simply shut down. Much of the discussion concerning this stage dwells not so much on the physical brutality as on the mental agony of personal insult and the demeaning obsession with food. The daily ration of about ten ounces of bread and one and three-quarters pints of watery soup was never adequate for the labor they were forced to perform.