This book was written with the purpose of proclaiming the duty of each individual to search for truth and the meaning of existence. The twentieth century produced such monsters as Hitler, Stalin, and Pol Pot who revealed the deadly drive of people who blindly followed these tyrants. Ignorance, passivity, and sheepish readiness to sell one's life into the hands of self-made political "saviors" have created the sad reality of our times. Our world today is characterized by a growing cult of political power. There is an almost complete neglect of the individual person and of moral values in general. We should always remember that those who neglect reflection sentence themselves to repeat the same catastrophes and mistakes. Thinking requires determination and endurance. It is not easy. It demands courage to question the most fundamental convictions that may be accepted by others without any reflection or evaluation. Thinking requires courage because it involves a certain risk and may lead to unexpected conclusions. Above all, passion for truth is necessary for every honest seeker. The Socratic saying, "an unexamined life is not worth living," is as true today as it ever was before.