By means of an applied analysis of the arguments advanced in the Italian political and cultural debate of the last ten years, the book offers a rigorous introduction to the fundamentals of argumentation theory. Numerous examples of fallacies are pointed out in the analysis of the texts by politicians, scientific scholars, journalists, and so on: a summary of the main fallacies analyzed in the book is introduced in the appendix. The study of fallacies does not aim at the development of argumentative tricks or rhetoric strategies to win the discussion, but rather aims at investigating the logical structure of informal discourses and analyzing the communication rules that allow a rational discussion between the speakers.