Eternal return

Eternal return (also known as "eternal recurrence") is a concept which posits that the universe has been recurring, and will continue to recur, in a self-similar form an infinite number of times across infinite time or space. It is a purely physical concept, involving no supernatural reincarnation, but the return of beings in the same bodies. The idea of eternal return occurs in a parable in Section 341 of The Gay Science, and also in the chapter "Of the Vision and the Riddle" in Thus Spoke Zarathustra, among other places.
Not only does Nietzsche posit that the universe is recurring over infinite time and space, but that the different versions of events that have occurred in the past may at one point or another take place again, hence "all configurations that have previously existed on this earth must yet meet..." And with each version of events is hoping that some knowledge or awareness is gained to better the individual hence "And thus it will happen one day that a man will be born again, just like me and a woman will be born, just like Mary - only that it is hoped to be that the head of this man may contain a little less foolishness..." Alexander Nehamas writes in Nietzsche: Life as Literature of three ways of seeing the eternal recurrence: "(A) My life will recur in exactly identical fashion." This expresses a totally fatalistic approach to the idea. "(B) My life may recur in exactly identical fashion." This second view conditionally asserts cosmology, but fails to capture what Nietzsche refers to in The Gay Science, 341. Finally, "(C) If my life were to recur, then it could recur only in identical fashion." Nehamas shows that this interpretation exists totally independently of physics and does not presuppose the truth of cosmology. Nehamas draws the conclusion that if individuals constitute themselves through their actions, then they can only maintain themselves in their current state by living in a recurrence of past actions (Nehamas 153). Nietzsche's thought is the negation of the idea of a history of salvation.