《墨子·35章 非命(上)》
说话没有准则，好比在陶轮之上，放立测量时间的仪器，就不可能弄明白是非利害之分了。所以言论有三条标准，哪三条标准呢？墨子说： 有本原的，有推究的，有实践的。 
故言必有三表。何谓三表？子墨子言曰：有本之者，有原之者，有用之者。
Speaking without principles is like placing a measuring device on a pottery wheel, impossible to understand the difference between right and wrong. Therefore, there are three criteria for speech. Which three criteria are there? Mozi said: "Based on the root, elaborated, and practical."