The analysis of the mind and the exploration of human motives and behavior are some of the breakthrough areas of study in the 19th and 20th century, shaped by visionary thinkers and landmark experiments. This documentary tracks the development of the first scientific approaches of Wilhelm Wundt, the practical applications of Sigmund Freud, the controversial philosophy of eugenics and the startling discovers of B.F. Skinner and Stanley Milgram.