"Crowds have always played a serious role in History, however never as significant a role as today. The unconscious action of crowds, as it is influenced by the actions of individuals, represents one of the characteristics of our era."

In this work, Le Bon articulates his theory on the impact of the masses on individual psychology and lays the groundwork for the science of social psychology. All the individual traits of a person, such as logic, consciousness, and critical thinking within the crowd, are diminished.

Crowds possess characteristics that are entirely different from those of the individuals that make them up. Different personalities merge into a singular entity of thought and emotion.

This book resonated particularly with the leaders of the 20th century and contributed to the construction of fascist regimes.