善无主于心者不留，行莫辩于身者不立。
善不是出自内心的，不能保留；行为不能从自身辩明的，不能去做。善不是出自内心的，只能够勉强支撑一时，必然不能长久。所以也只能使伪善。
The man who is fit to work at any particular trade is unable to understand the science of that trade without the help and guidance of those who are working with him or over him.
解释：别人爱我，我也爱人；别人厌恶我，我也讨厌别人。