Frankl says the meaning of life lies in finding the "right answer" to the problems of life. Since everyone has different problems, the actual "meaning" is different for everyone, but the common principle lies in service to others, which for Frankl is the highest expression of love. As long as a person knows the "why" of their existence, Frankl says, they will be able to endure any "how."
Frankl provides many examples from his experience in the concentration camp about the will to live and the importance of having a sense of purpose. For instance, he writes about how he was able to endure the suffering of the camp by imagining himself in the future delivering lectures about camp psychology to rapt audiences. While this may seem like idle daydreaming, Frankl sees such things as central to maintaining hope and ensuring survival. He came to understand that one of his purposes was to be able to understand the psychology of the camp. This he felt he could do in a unique way. Because of this purpose, he was able to externalize the physical suffering he experienced. Unlike other prisoners who would abandon hope and give up on life, Frankl was driven by this sense of purpose, which humanized him.