The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt, and the profoundest wisdom to know when it ought to be resisted, and when it be obeyed.

在广州全国学生评议会的演说，1923年8月15日

只有准备充分，才可能成功。

认证计划不仅仅是木制品上的贴纸；它们代表了对我们星球的承诺。