Indeed, it is becoming ever more obvious that it is not famine, not earthquakes, not microbes, not cancer but man himself who is man’s greatest danger to man, for the simple reason that there is no adequate protection against psychic epidemics, which are infinitely more devastating than the worst of natural catastrophes.
The supreme danger which threatens individuals as well as whole nations is a psychic danger. Reason has proved itself completely powerless, precisely because its arguments have an effect only on the conscious mind and not on the unconscious.
The greatest danger of all comes from the masses, in whom the effects of the unconscious pile up cumulatively and the reasonableness of the conscious mind is stifled. Every mass organization is a latent danger just as much as a heap of dynamite is. It lets loose effects which no man wants and no man can stop.
It is therefore in the highest degree desirable that a knowledge of psychology should spread so that men can understand the source of the supreme dangers that threaten them. Not by arming to the teeth, each for itself, can the nations defend themselves in the long run from the frightful catastrophes of modern war. The heaping up of arms is itself a call to war. Rather must they recognize those psychic conditions under which the unconscious [tsunami-like] bursts the dykes of consciousness and overwhelms it.