We speak of historical currents and trends, but we should be careful to remember that they do not descend on humanity from afar: they come from humanity itself. We can often say where they began, which hand helped them grow or put up obstacles in their path. And even when the human crowd allows itself to be carried away, we can sometimes perceive a sole man who goes against the flow, and, in some cases, is followed thereafter by the others. French text. Revised edition (original 1892), with an introduction by Jacques Roubaud and a study by Max Engammare.