The example which precedes is of the simplest. Its appositeness will be easily perceived. It did not escape the attention of such a psychologist as Napoleon, but our modern legislators, ignorant as they are of the characteristics of a crowd, are unable to appreciate it. Experience has not taught them as yet to a sufficient degree that men never shape their conduct upon the teaching of pure reason. Many other practical applications might be made of the psychology of crowds. A knowledge of this science throws the most vivid light on a great number of historical and economic phenomena totally incomprehensible without it. I shall have occasion to show that the reason why the most remarkable of modern historians, Taine, has at times so imperfectly understood the events of the great French Revolution is, that it never occurred to him to study the genius of crowds. He took as his guide in the study of this complicated period the descriptive method resorted to by naturalists; but the moral forces are almost absent in the case of the phenomena which naturalists have to study. Yet it is precisely these forces that constitute the true mainsprings of history. In consequence, merely looked at from its practical side, the study of the psychology of crowds deserved to be attempted. Were its interest that resulting from pure curiosity only, it would still merit attention. It is as interesting to decipher the motives of the actions of men as to determine the characteristics of a mineral or a plant. Our study of the genius of crowds can merely be a brief synthesis, a simple summary of our investigations. Nothing more must be demanded of it than a few suggestive views. Others will work the ground more thoroughly. To-day we only touch the surface of a still almost virgin soil. BOOK I THE MIND OF CROWDS CHAPTER I GENERAL CHARACTERISTICS OF CROWDS.--PSYCHOLOGICAL LAW OF THEIR MENTAL UNITY. What constitutes a crowd from the psychological point of view--A numerically strong agglomeration of individuals does not suffice to form a crowd--Special characteristics of psychological crowds--The turning in a fixed direction of the ideas and sentiments of individuals composing such a crowd, and the disappearance of their personality--The crowd is always dominated by considerations of which it is unconscious--The disappearance of brain activity and the predominance of medullar activity--The lowering of the intelligence and the complete transformation of the sentiments--The transformed sentiments may be better or worse than those of the individuals of which the crowd is composed--A crowd is as easily heroic as criminal.