This term means to ascertain the similarities and differences between things by classifying them. This phrase originated in The Book of Changes, which regarded everything in the world as belonging to different categories, and those with similar features being in the same group. Thus, one can tell the similarities and differences of things by grouping those that have common features. This concept also alerts people that they should be careful in interacting with people and should stick to like-minded people and those with moral integrity.

The upper trigram is qian, which is the image of heaven. The lower trigram is li, which is the image of fire. These form the hexagram for “fellowship.” A man of virtue discerns similarities and differences in things based on how they are classified. The Book of Changes