郑人有且置履者，先自度其足而置之其坐，至之市而忘操之。已得履，乃曰：“吾忘持度，反归取之。”及反，市罢，遂不得履。人曰：“何不试之以足？”曰：“宁信度，无自信也。”

— Han Feizi, circa 2ⁿᵈ century BCE

There once lived a man in the state of Zheng who was about to buy shoes. He had measured his feet beforehand, and placed the results on a chair. He forgot to take the mensural tool with him and reached the market. Having chosen the shoes he wanted, he said, 'I forgot to bring the mensural tool with me. I need to go home and take them.' But when he returned, the market was closed and he eventually did not get those shoes. People asked him, "Why did you not just try on the shoes?" To this he replied, "I would rather believe the measurements, I don't trust myself."