This book traces the principal roots of the concept of post-truth to uncover how it came by its present meaning. The concept of post-truth is the ripe and poisonous fruit of a tree fertilized and watered by many gardeners: some with good intentions, some with bad intentions, and others without a full understanding of the consequences of their thoughts and actions. If the concepts behind the expression ¿post-truth¿ have a long history, what is behind the current rise in interest and alarm about the concept? Chosen by the Oxford English Dictionary as ¿word of the year¿ in 2016, post-truth has entered both journalistic and common languages.