信言不美，美言不信(xn yn b měi，měi yn b xn)
可信的话并不漂亮，漂亮的话多不可信。老子鉴于当时社会风气与文风的浮华不实，倡导返朴归真与自然平淡的生活方式和文学风格。魏晋时代，文人崇尚自然素朴，反对虚浮华丽的创作风气，出现了像陶渊明这样伟大的诗人，文艺创作也倡导真实自然的思想与风格。自此之后，中国古代文艺以素朴自然为最高的审美境界。
Trustworthy Words May Not Be Fine-sounding; Fine-sounding Words May Not Be Trustworthy.
To address the extravagance in social mores and in the style of writing of his time, Laozi advocated simple and natural lifestyles and literary presentations. During the Wei and Jin dynasties, men of letters valued natural and simple literary styles and were opposed to extravagant and superficial styles. This line of thought led to the emergence of great poets like Tao Yuanming, and shaped literary writings to reflect direct thoughts and natural expressions. Subsequently, ancient Chinese literature and art took simplicity and naturalness as the highest aesthetic standards.
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【引例】
信言不美，美言不信。善者不辩，辩者不善。(《老子八十一章》)
老子疾伪，故称美言不信，而五千精妙，则非弃美矣。(刘勰《文心雕龙情采》)
Trustworthy words may not be fine-sounding; fine-sounding words may not be trustworthy. A kind-hearted person may not be an eloquent speaker; a glib person is often not kind. (Laozi)
Laozi detested pretense, so he said, Flowery rhetoric words may not be trustworthy. However, the 5,000-word Dao De Jing (another name of Laozi) he wrote is not only profound in ideas but reads beautifully. That means he was not opposed to writings using fine words. (Liu Xie: The Literary Mind and the Carving of Dragons)