Irvin D. Yalom examines the four main concepts of psychotherapy: the inevitability of death, the freedom to shape our own lives, our ultimate aloneness, and the absence of any obvious meaning or sense to life.
If death is inevitable, if all of our accomplishments, indeed our entire solar system, shall one day lie in ruins, if the world is contingent (that is, everything could as well have been otherwise), if human beings must construct the world and the human design within that world, then what enduring meaning can there be in life? … We are meaning-seeking creatures. Biologically, our nervous systems are organized in such a way that the brain automatically clusters incoming stimuli into configurations. Meaning also provides a sense of mastery: feeling helpless and confused in the face of random, unpatterned events, we seek to order them and, in so doing, gain a sense of control over them. Even more important, meaning gives birth to values and, hence, to a code of behavior: thus the answer to why questions (Why do I live?) supplies an answer to how questions (How do I live?).