The idea of eternal return is a mysterious one, and Nietzsche has often perplexed other philosophers with it: to think that everything recurs as we once experienced it, and that the recur¬rence itself recurs ad infinitum! What does this mad myth signify?
Putting it negatively, the myth of eternal return states that a life which disappears once and for all, which does not return, is like a shadow, without weight, dead in advance, and whether it was horrible, beautiful, or sublime, its horror, sublimity, and beauty mean nothing. We need take no more note of it than of a war between two African kingdoms in the fourteenth century, a war that altered nothing in the destiny of the world, even if a hundred thousand blacks perished in excruciating torment.
Will the war between two African kingdoms in the four¬teenth century itself be altered if it recurs again and again, in eternal return?
It will: it will become a solid mass, permanently protuber¬ant, its inanity irreparable.
If the French Revolution were to recur eternally, French historians would be less proud of Robespierre. But because they deal with something that will not return, the bloody years of the Revolution have turned into mere words, theories, and discus¬sions, have become lighter than feathers, frightening no one. There is an infinite difference between a Robespierre who oc¬curs only once in history and a Robespierre who eternally re¬turns, chopping off French heads.
Let us therefore agree that the idea of eternal return im¬plies a perspective from which things appear other than as we know them: they appear without the mitigating circumstance of their transitory nature. This mitigating circumstance prevents us from coming to a verdict. For how can we condemn some¬thing that is ephemeral, in transit? In the sunset of dissolution, everything is illuminated by the aura of nostalgia, even the guillotine.
Not long ago, I caught myself experiencing a most incred¬ible sensation. Leafing through a book on Hitler, I was touched by some of his portraits: they reminded me of my childhood. I grew up during the war; several members of my family perished in Hitler's concentration camps; but what were their deaths compared with the memories of a lost period in my life, a period that would never return?
This reconciliation with Hitler reveals the profound moral perversity of a world that rests essentially on the nonexistence of return, for in this world everything is pardoned in advance and therefore everything cynically permitted.

                                             by milan kundera

                                                     from   the unbearable lightness of being