充足理由律 (Principle of sufficient reason) (event)

https://zh.wikipedia.org/wiki/%E5%85%85%E8%B6%B3%E7%90%86%E7%94%B1%E5%BE%8B

https://en.wikipedia.org/wiki/Principle_of_sufficient_reason

https://en.wikipedia.org/wiki/Nothing_comes_from_nothing

事出必有因 no event occurs without a cause or a reason