Idioms and extended meaning of "直(straight)" and "弯(curved)" in Chinese

直 straight ; 弯(曲) curved

The character "直" in Chinese can also represent the meaning of a person's frank personality.
For example, "直肠子" seems to mean "a straight tharm" in word, but actually the word represents a frank character. 
If you are described as a "直肠子"man, it doesn't mean that you have a straight tharm, but means you are forthright in character.

Representative personae: Li Kui (a character in Chinese traditional novel"《水浒传》（Water Margin）")

http://en.wikipedia.org/wiki/Li_Kui_(Water_Margin)

http://en.wikipedia.org/wiki/Water_Margin

(The pictures are from http://www.gh365.com.cn/2009/d1.htm 国画365)

In Chinese, the character "直(straight)" and "弯(curved)" implicate the abstract meaning of "right" and "wrong".

是非曲直(shì fēi qǔ zhí): the rights and wrongs

是：be, yes, right    非：not, non-, wrong

曲(弯)：curved      直：straight

Here the "straight" and "curved" could be extended in the meaning of "right" and "wrong".

So we combine these four words to describe the meaning of "the rights and wrongs".

纵曲枉直(zòng qǔ wǎng zhí): to indulge the wrong and treat the right unjustly

出处：《抱朴子·内篇·微旨》：“纵曲枉直，废公为私，刑加无辜。”

Example: The Injustice to Dou E   http://en.wikipedia.org/wiki/The_Injustice_to_Dou_E

The picture is download from http://www.hwjyw.com/zhwh/traditional_culture/zgwx/zmzp/200710/t20071009_8258.shtml