The opinions and beliefs you believe in are what shape your life, whether happy or miserable, and it is also what determines your fate in the end! Le Bon deals with the relationship between a person and his beliefs and opinions, which is a very sensitive relationship and influence on the course of the individual, starting with general definitions that differentiate between opinion and belief, And their relationship with knowledge, touching on the mechanisms of forming opinion and belief and being influenced by them, psychologically and realistically. Le Bon asks: What moves us regarding what we believe? What is the role of instinct in this? What is the cause of the conflict resulting from different opinions? How can we establish consensus between the parties in belief? How is collective opinion formed and spread? Reviewing methods of promotion and their role, in addition to many topics that make the book an indispensable reference for every student and researcher in politics, society, and history. Today, we may be in dire need to learn about the thought of this exceptional writer at a time when differences of opinion have divided the bodies of countries and peoples and we are divided within one house, not just society.