Friedrich Nietzsche (1844 – 1900) claimed his doctrine of eternal return was his most important idea, the “greatest elevation of the consciousness of strength in a man.” On it, he says “My philosophy brings the triumphant idea of which all other modes of thought will ultimately perish.”

But it’s a difficult concept to grasp—it also isn’t clear if Nietzsche believed in eternal return as a cosmological fact or only as a thought experiment—and he died before he finished his logical proof of the idea.

What is eternal return?

Eternal return (or eternal recurrence) is the idea that after we die, we will live out our life again in exactly the same way—with every thought we’ve ever had and every action we’ve ever taken repeated—over and over again forever.

Nietzsche describes eternal return in his book The Gay Science:

“What, if some day or night a demon were to steal after you into your loneliest loneliness and say to you: ‘This life as you now live it and have lived it, you will have to live once more and innumerable times more; and there will be nothing new in it, but every pain and every joy and every thought and sigh and everything unutterably small or great in your life will have to return to you, all in the same succession and sequence.”

The physics behind eternal return isn’t proven but the idea is as follows: if time is infinite and there’s a finite amount of energy in the universe, every possible combination of events must occur, and then repeat itself in the same order in an infinite loop.

Principle I: Eternal return is the idea that our lives will repeat themselves in the same way forever.

Permanence creates significance

Nietzsche posits that if life only happens once, life is insignificant—our actions don’t really matter because they will never be repeated. For example, while the French Revolution was atrocious, it isn’t as horrible because it will never happen again:

“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 discussions, have become lighter than feathers, frightening no one […] In the sunset of dissolution, everything is illuminated by the aura of nostalgia, even the guillotine.” – Milan Kundera, from The Unbearable Lightness of Being

And interestingly, Nietzsche says life is too important to lack significance:

“A certain emperor always bore in mind the transitoriness of all things so as to not take them too seriously and to live at peace among them. To me, on the contrary, everything seems far too valuable to be so fleeting: I seek an eternity for everything: ought one to pour the most precious salves and wines into the sea?— My consolation is that everything that has been is eternal: the sea will cast it up again.” – from The Will to Power

Under eternal return, our lives repeat identically forever. Our current actions then hold the highest significance and weight because they are permanent, bound to recur for eternity. In this way, eternal return is an antidote to nihilism (the belief that life is meaningless)—every single action holds substantial meaning.

Principle II: Eternal return implies our actions are infinitely significant.

The heaviest burden

Eternal return puts pressure on us; our actions carry great weight, we are responsible for our own fate, and we have to live with every decision we make forever. 

If eternal return exists, life holds equal tragedy as promise. It means our future lives are predetermined by our current life. So if you don’t like your life or are living unethically, you better fix it or you’re bound to experience your own personal hell forever. 

“If every second of our lives recurs an infinite number of times, we are nailed to eternity as Jesus Christ was nailed to the cross. It is a terrifying prospect. In the world of eternal return the weight of unbearable responsibility lies heavy on every move we make. That is why Nietzsche called the idea of eternal return the heaviest of burdens.” – Milan Kundera from The Unbearable Lightness of Being 

Principle III: Eternal return gives us agency in our current lives but it creates the utmost urgency to live well now.

A higher standard of living

It’s difficult to believe that eternal return is a cosmological reality. How can our lives repeat identically forever? But eternal return is a possibility—it hasn’t been disproven. And at the very least, we can view it as a thought experiment.

It forces us to rethink our decisions and values. For instance, Nietzsche says:

“If this thought gained possession of you, it would change you as you are or perhaps crush you. The question in each and every thing, ‘Do you desire this once more and innumerable times more?’ would lie upon your actions as the greatest weight.” – from Nietzsche’s The Gay Science

What would you do differently if you knew eternal return was real? Would you stop spending time with certain people or leave a relationship that isn’t working? Would you quit the job you hate and stop making bad decisions?   

Eternal return should force us to have a higher standard for life—the people we let into our lives, how we spend our time, our morals, and the consideration we give decisions (especially important ones).

Principle IV: Eternal return forces a higher standard of life.  

Do you think eternal return is a possibility? How would you change your life if you knew it was real? Leave your thoughts in the comments below! 

If you liked this post, check out these:

The paradox of chaos theory

The interconnectedness of the world and time

Time: why it's important not to squander and how to spend it