Logotherapy was developed by neurologist and psychiatrist Viktor Frankl and is based on the premise that the primary motivational force of an individual is to find a meaning in life. Frankl describes it as "the Third Viennese School of Psychotherapy" along with Freud's psychoanalysis and Adler's individual psychology. Logotherapy is based on an existential analysis focusing on Kierkegaard's will to meaning as opposed to Alfred Adler's Nietzschean doctrine of will to power or Freud's will to pleasure. Rather than power or pleasure, logotherapy is founded upon the belief that striving to find meaning in life is the primary, most powerful motivating and driving force in humans. A short introduction to this system is given in Frankl's most famous book, Man's Search for Meaning (1946), in which he outlines how his theories helped him to survive his Holocaust experience and how that experience further developed and reinforced his theories. Presently, there are a number of logotherapy institutes around the world. The notion of logotherapy was created with the Greek word logos ("meaning"). Frankl's concept is based on the premise that the primary motivational force of an individual is to find meaning in life. The following list of tenets represents basic principles of logotherapy: Life has meaning under all circumstances, even the most miserable ones. Our main motivation for living is our will to find meaning in life. We have freedom to find meaning in what we do, and what we experience, or at least in the stance we take when faced with a situation of unchangeable suffering. The human spirit is referred to in several of the assumptions of logotherapy, but the use of the term spirit is not "spiritual" or "religious". In Frankl's view, the spirit is the will of the human being. The emphasis, therefore, is on the search for meaning, which is not necessarily the search for God or any other supernatural being. Frankl also noted the barriers to humanity's quest for meaning in life. He warns against "...affluence, hedonism, [and] materialism.