说苑/曾子曰：「狎甚則相簡也，莊甚則不親。

曾子曰：「狎甚則相簡也，莊甚則不親。

Eric Henry

Zengzi said, “Excessive familiarity leads to rudeness and excessive gravity to coldness.

是故君子之狎，足以交懽；莊，足以成禮而已。」

Eric Henry

A man of quality, therefore, is no more familiar than he needs to be to induce mutual pleasure and is no graver than he needs to be to fulfill ritual norms.” “Discourse on Fine and Hateful Birds” (Lingqin e’niao lun 令禽惡鳥論) of Cao Zhi 曹植 is based on this item.

Eric Henry

This can be found in Chen Siwang ji 陳思王集, a Ming dynasty collection of Cao Zhi’s poetry.