We read history to take the past as a mirror and avoid wrong turns.
Tips
history
The middle one of three mirrors in the words of 唐太宗 on the death of his minister 魏征 in 643: bronze shows you your robes, other people show you your mistakes, and the past, 以古为镜，可以知兴替, shows why dynasties rise and fall.
usage
The 新唐书 gives the line as 以古为鉴, and today the usual form is 以史为鉴 'take history as a lesson'.
