《论衡·卷三十·自纪篇》
它的光辉像天上的日月星辰一般灿烂，条理像地上的山脉河流一样清楚，凡是不清楚不明白的问题，全都能说得清清楚楚，况且事物的名目一旦表示清楚了，所论述的事情也就确定无疑了。《论衡》这本书，就是衡量言论是非的标准。
吾文未集於简札之上，藏於胸臆之中，犹玉隐珠匿也；及出露，犹玉剖珠出乎，烂若天文之照，顺若地理之晓，嫌疑隐微，尽可名处。且名白，事自定也。《论衡》者，论之平也。
Its brilliance is like the sun, moon, and stars in the sky, and its organization is like the mountains and rivers on earth. All unclear issues can be clearly explained. Moreover, once the names of things are defined clearly, the things being discussed are also determined. The book "Inquiry about Points of Dispute" is just the standard for measuring the pros and cons of speech.