“Duck typing” is a concept in computer science “If it walks like a duck and it quacks like a duck, then it must be a duck”(https://en.wikipedia.org/wiki/Duck_typing). I found a very similar statement in Yang Xiong’s 法言: 假儒衣書，服而讀之，三月不歸，孰曰非儒也 When someone dresses like a Confucianism, reads like a Confucianism, works hard like a Confucianism. This person is a Confucianism.