A crowd is at the mercy of all external exciting causes, and reflects their incessant variations. It is the slave of the impulses which it receives. The isolated individual may be submitted to the same exciting causes as the man in a crowd, but as his brain shows him the inadvisability of yielding to them, he refrains from yielding. This truth may be physiologically expressed by saying that the isolated individual possesses the capacity of dominating his reflex actions, while a crowd is devoid of this capacity.
