On the 小取 Xiaoqu Chapter of the Mo Zi and Chinese Logic
Ⓒ 2012 Patrick Edwin Moran

This chapter of the Mo Zi gives a critique of Mohist philosophy in terms of its logic. It contrasts Mohist conclusions with the conclusions of "the rest of the world."

All of the discussions in the "Xiaoqu" chapter that I will discuss have to do with sets and sub-sets. Let's establish a convention: If I write a pair of parentheses, please connect the tops of the parentheses with each other and connect their bottoms. That will make an oval, which will represent one set. If I write curly braces, then do the same thing. And also do the same thing for square braces. So
(animals {dogs})
would be the set of animals and the subset of dogs, and
[animals { four-legged ( * } hairless)]
would represent the set of all animals, and two intersecting sub-sets, the set of four-legged creatures and the set of hairless creatures. At the * part of the diagram are the creatures that are both four-legged and hairless.