In crowds it is stupidity and not mother wit that is accumulated.

The precise moment at which a great belief is doomed is easily recognisable; it is the moment when its value begins to be called in question.

The real cause of the great upheavals which precede changes of civilisations, such as the fall of the Roman Empire and the rise of the Arabian Empire, is a profound modification in the ideas of the peoples .... The memorable events of history are the visible effects of the invisible changes of human thought .... The present epoch is one of these critical moments in which the thought of mankind is undergoing a process of transformation.

The influence of the leaders is due in very small measure to the arguments they employ, but in a large degree to their prestige. The best proof of this is that, should they by any circumstance lose their prestige, their influence disappears.

The images evoked by words being independent of their sense, they vary from age to age and from people to people, the formulas remaining identical. Certain transitory images are attached to certain words: the word is merely as it were the button of an electric bell that calls them up.

At the bidding of a Peter the Hermit millions of men hurled themselves against the East; the words of an hallucinated enthusiast such as Mahomet created a force capable of triumphing over the Graeco-Roman world; an obscure monk like Luther bathed Europe in blood. The voice of a Galileo or a Newton will never have the least echo among the masses. The inventors of genius hasten the march of civilization. The fanatics and the hallucinated create history.

If atheism spread, it would become a religion as intolerable as the ancient ones.