夫物多相类而非也。幽莠之幼也似禾,骊牛之黄也似虎,白骨疑象,武夫类玉,此皆似之而非者也。· There are many cases of two things looking alike but being different in nature. Green bristlegrass looks like crops; a black-and-yellow-coloured ox looks like a tiger from afar; a piece of white bone looks like ivory; and a piece of Wufu stone looks like jade. All these are examples of things seemingly the same but different in nature.
(Strategies of the Warring States [475 BC-221 BC])