This book was the end product of life experiences, thoughts and intellectual wanderings of the author, who through his career and for the last twenty years was always serving all the three aspects of a Psychiatrist: He is a clinician, a researcher and an academic teacher. The book includes a comprehensive history of Psychiatry since antiquity and until today, with an emphasis not only on main events but also specifically and with much detail and explanations, on the chain of events that led to a particular development. At the center of this work is the question ‘What is mental illness?’ and ‘Does free will exist?’. These are questions which tantalize Psychiatrists, neuroscientists, psychologists, philosophers, patients and their families and the sensitive and educated lay persons alike. Thus, the book includes a comprehensive review and systematic elaboration on the definition and the concept of mental illness, a detailed discussion on the issue of free will as well as the state of the art of contemporary Psychiatry and the socio-political currents it has provoked. Finally the book includes a description of the academic, social and professional status of Psychiatry and Psychiatrists and a view of future needs and possible developments. A last moment addition was the chapter on conspiracy theories, as a consequence of the experience with the social media and the public response to the COVID-19 outbreak which coincided with the final stage of the preparation of the book. Their study is an excellent opportunity to dig deep into the relation among human psychology, mental health, the society and politics and to swim in intellectually dangerous waters.