“The soldier is convinced that a certain indefinitely extendable time period is accorded him before he is killed, the burglar before he is caught, men in general, before they must die. That is the amulet which preserves individuals — and sometimes populations — not from danger, but from the fear of danger, in reality from the belief in danger, which in some cases allows them to brave it without being brave. Such a confidence, just as unfounded, supports the lover who counts on a reconciliation, a letter.”