translation.en: People have been debating the causes of happiness for a really long time, in fact for thousands of years, but it seems like many of those debates remain unresolved.
translation.zh: 很长一段时间，大家都在争论到底是什么带给人类 幸福感，事实上这场争论已经持续了数千年之久， 但是看起来这些争论都没有令人信服的结果。