Taiwan pr. [fa2 zi5]
Know yourself and know your enemy, and you will never be defeated (idiom, from Sunzi's Art of War 孫子兵法|孙子兵法[Sūn zǐ Bīng fǎ]).
Seven Military Classics of ancient China viz "Six Secret Strategic Teachings” 六韜|六韬[Lìu Tāo], “Methods of Sima” 司馬法|司马法[Sī mǎ Fǎ], ”Art of War” 孫子兵法|孙子兵法[Sūn zǐ Bīng Fǎ], “Wu-zi” 吳子|吴子[Wú zǐ], “Wei Liao-zi” 尉繚子|尉缭子[Wèi Liáo zi], ”Three Strategies of Huang Shigong” 黃石公三略|黄石公三略[Huáng Shí gōng Sān Lüè] and ”Duke Li of Wei answering Emperor Taizong of Tang” 唐太宗李衛公問對|唐太宗李卫公问对[Táng Tài zōng Lǐ Wèi Gōng Wèn Dùi]
”Three Strategies of Huang Shigong”, also known as Taigong Bing Fa 太公兵法[Tài gōng Bīng Fǎ], one of the Seven Military Classics of ancient China 武經七書|武经七书[Wǔ jīng Qī Shū], variously attributed to Jiang Ziya 薑子牙|姜子牙[Jiāng Zǐ yá], Huang Shigong 黃石公|黄石公[Huáng Shí gōng] or an anonymous author
lit. hair and beard all in one stroke
fig. to handle different things by the same method
one method to solve all problems
one size fits all