The varying impulses to which crowds obey may be, according to their exciting causes, generous or cruel, heroic or cowardly, but they will always be so imperious that the interest of the individual, even the interest of self-preservation, will not dominate them.The exciting causes that may act on crowds being so varied, and crowds always obeying them, crowds are in consequence extremely mobile. This explains how it is that we see them pass in a moment from the most bloodthirsty ferocity to the most extreme generosity and heroism. A crowd may easily enact the part of an executioner, but not less easily that of a martyr. It is crowds that have furnished the torrents of blood requisite for the triumph of every belief. It is not necessary to go back to the heroic ages to see what crowds are capable of in this latter direction. They are never sparing of their life in an insurrection, and not long since a general,[1]becoming suddenly popular, might easily have found a hundred thousand men ready to sacrifice their lives for his cause had he demanded it.