种树的最佳时间是20年前。第二好的时间就是现在。

艺术越个人化，就越普遍。

The obligation of subjects to the sovereign is understood to last as long, and no longer, than the power lasteth by which he is able to protect them.

过去是一个影子，总是跟随，但从未追上。

解决问题是智能系统的核心活动。