hé tóngyì 合同异
Unify Similarity and Difference
The philosopher Hui Shi’s approach to similarity and difference among things was to unite them, regarding similarities and differences as relative. There are bound to be small or great similarities and differences between any two concrete things. If we look at them from the point of view of similarity, all things have something in common, so they can be said to be similar. If we look at them from the point of view of difference, no two things are completely the same, so they are all different. Whether things are similar or different depends on the perspective from which we look at them. This led Hui Shi to determine that similarities and differences are not separate; that is, they are unified.
When there are major commonalities and minor differences, or minor commonalities and major differences, it is called “minor commonality and differentiation.” When things are totally identical or totally different, it is called “major commonality and differentiation.” (Zhuangzi)