In 1789 a ferment arises in Paris; it grows, spreads, and is expressed by a movement of peoples from west to east. Several times it moves eastward and collides with a countermovement from the east westward. In 1812 it reaches its extreme limit, Moscow, and then, with remarkable symmetry, a countermovement occurs from east to west, attracting to it, as the first movement had done, the nations of middle Europe. The counter movement reaches the starting point of the first movement in the west⁠—Paris⁠—and subsides.

During that twenty-year period an immense number of fields were left untilled, houses were burned, trade changed its direction, millions of men migrated, were impoverished, or were enriched, and millions of Christian men professing the law of love of their fellows slew one another.

What does all this mean? Why did it happen? What made those people burn houses and slay their fellow men? What were the causes of these events? What force made men act so? These are the instinctive, plain, and most legitimate questions humanity asks itself when it encounters the monuments and tradition of that period.