Who wrote the book "Man's Search for Meaning"?

"Man's Search for Meaning" is a 1946 book by Viktor Frankl chronicling his experiences as an Auschwitz concentration camp inmate during World War II, and describing his psychotherapeutic method, which involved identifying a purpose in life to feel positively about, and then immersively imagining that outcome. According to Frankl, the way a prisoner imagined the future affected his longevity. Frankl also concludes that there are only two races of men, decent men and indecent. No society is free of either of them, and thus there were "decent" Nazi guards and "indecent" prisoners, most notably the prisoner functionaries  who would torture and abuse their fellow prisoners for personal gain.

Frankl concludes from his experience that a prisoner's psychological reactions are not solely the result of the conditions of his life, but also from the freedom of choice he always has even in severe suffering. The inner hold a prisoner has on his spiritual self relies on having a hope in the future, and that once a prisoner loses that hope, he is doomed.

The title of the first English-language translation was "From Death-Camp to Existentialism". The book's common full English title is "Man's Search for Meaning: An Introduction to Logotherapy", although this subtitle is often not printed on the cover of modern editions.