<P> An allusion to eternal recurrence also occurs at the conclusion of Browne's The Garden of Cyrus . </P> <P> All things began in order, so shall they end, and so shall they begin again . </P> <P> The concept of "eternal recurrence", the idea that with infinite time and a finite number of events, events will recur again and again infinitely, is central to the writings of Friedrich Nietzsche . As Heidegger points out in his lectures on Nietzsche, Nietzsche's first mention of eternal recurrence, in aphorism 341 of The Gay Science (cited below), presents this concept as a hypothetical question rather than postulating it as a fact . According to Heidegger, it is the burden imposed by the question of eternal recurrence--whether or not such a thing could possibly be true--that is so significant in modern thought: "The way Nietzsche here patterns the first communication of the thought of the' greatest burden' (of eternal recurrence) makes it clear that this' thought of thoughts' is at the same time' the most burdensome thought ."' </P> <P> The thought of eternal recurrence appears in a few of his works, in particular § 285 and § 341 of The Gay Science and then in Thus Spoke Zarathustra . The most complete treatment of the subject appears in the work entitled Notes on the Eternal Recurrence, a work which was published in 2007 alongside Søren Kierkegaard's own version of eternal return, which he calls' repetition' . Nietzsche sums up his thought most succinctly when he addresses the reader with: "Everything has returned . Sirius, and the spider, and thy thoughts at this moment, and this last thought of thine that all things will return". However, he also expresses his thought at greater length when he says to his reader: </P>

What 4 occurrences needed to occur for life to appear on earth