人之相知，贵在知心。——汉·李陵

 

人之相识，贵在相知，人之相知，贵在知心。——孟子

 

The friendship between gentlemen appears indifferent but is pure like water; the friendship between mean men is as sweet as wine.

 

——Confucius

 

君子之交淡如水;小人之交甘若醴。