 Parmenides, another pre-Socratic, implicitly appeals to the PSR when he claims that the world cannot have come into existence because then it would have come from nothing (Fragment B8 9–10). Nothing comes from nothing. If it did, Parmenides asks, why did it not come into existence at an earlier or a later time? Parmenides appears to reason as follows. If the world came into existence, the actual moment that it came into existence would be arbitrary. It would be a brute fact. There are no brute facts (the PSR). So, the world did not come into existence.