Viktor E. Frankl was Professor of Neurology and Psychiatry at the University of Vienna Medical School. He spent three years during World War II in concentration camps, including Theresienstadt, Auschwitz, and Dachau, where he formulated many of his key ideas. Logotherapy, his psychotherapeutic school, is founded on the belief that striving to find meaning in life is the most powerful motivation for human beings. Frankl wrote 39 books, which were published in 38 languages. His best-known, Man's Search for Meaning, gives a firsthand account of his experiences during the Holocaust, and describes the psychotherapeutic method he pioneered. The Library of Congress called it one of "the ten most influential books in America." Frankl lectured on five continents.