By extension, this principle can be applied in many fields.
Tips
history
From Xiao Tong's preface to the Wen Xuan (《文选·序》): 推而广之,不可胜载矣 - 'extending it more broadly, one could not exhaust the list.' Originally a prose rhetorical move; now a common academic transition.
usage
Formal register. Marks a generalization in essays, speeches, and arguments - often at the start of a sentence: 推而广之,... Apostrophe in pinyin signals the e-initial syllable 'ér' for clarity.