What little insight we can get into these forces must be sought for in the general course of the evolution of a people, and not in the isolated facts from which this evolution appears at times to proceed. Were these facts alone to be taken into consideration, history would seem to be the result of a series of improbable chances. It was improbable that a Galilean carpenter should become for two thousand years an all-powerful God in whose name the most important civilisations were founded; improbable, too, that a few bands of Arabs, emerging from their deserts, should conquer the greater part of the old Graco-Roman world, and establish an empire greater than that of Alexander; improbable, again, that in Europe, at an advanced period of its development, and when authority throughout it had been systematically hierarchised, an obscure lieutenant of artillery should have succeeded in reigning over a multitude of peoples and kings. Let us leave reason, then, to philosophers, and not insist too strongly on its intervention in the governing of men. It is not by reason, but most often in spite of it, that are created those sentiments that are the mainsprings of all civilisation--sentiments such as honour, self- sacrifice, religious faith, patriotism, and the love of glory. CHAPTER III THE LEADERS OF CROWDS AND THEIR MEANS OF PERSUASION 1. THE LEADERS OF CROWDS. The instinctive need of all beings forming a crowd to obey a leader--The psychology of the leaders of crowds--They alone can endow crowds with faith and organise them--The leaders forcibly despotic--Classification of the leaders--The part played by the will. 2. THE MEANS OF ACTION OF THE LEADERS. Affirmation, repetition, contagion--The respective part of these different factors--The way in which contagion may spread from the lower to the upper classes in a society--A popular opinion soon becomes a general opinion. 3. PRESTIGE. Definition of prestige and classification of its different kinds--Acquired prestige and personal prestige--Various examples--The way in which prestige is destroyed. We are now acquainted with the mental constitution of crowds, and we also know what are the motives capable of making an impression on their mind. It remains to investigate how these motives may be set in action, and by whom they may usefully be turned to practical account. 1. THE LEADERS OF CROWDS. As soon as a certain number of living beings are gathered together, whether they be animals or men, they place themselves instinctively under the authority of a chief.