In his book "Opinions and Beliefs", the doctor and historian Gustav Lebon deals with several concepts related to the opinions and beliefs of individuals, then provides their divisions, and provides an experimental investigation related to the formation of beliefs and the creation and emotional events that arise from them. Gustave explains the types of instincts that will direct individuals towards certain beliefs, and move them towards collective or individual opinions, as these engines deal with the details of their careful work and influences that call for collision with each other or consensus within the framework of societies. It shows a person's relationship with his opinions and beliefs that he believes in, and evacuates the differences between opinions, beliefs and knowledge, as it provides their manifestations on the behaviors and psychology of individuals. It discusses the issue of individual opinion, explaining its concept, which is considered the privacy of its most prominent manifestations, and the influences that would define these specifics among individuals, based on the impact of this on the opinions of groups, or public opinion for them. Gustav deals with ways to spread opinions between groups and the means of promotion used to transfer them, and discusses the continuity of their effectiveness through innovative social communication mechanisms.