From Sima Qian's (
司马迁) 《
报任安书》 (Letter to Ren An):
究天人之际,
通古今之变,
成一家之言 — 'to plumb the boundary between Heaven and man, to comprehend the changes of ancient and present, and so establish the words of one school.' This triad is the most famous statement of purpose in the Chinese historiographical tradition, often invoked when discussing what history is for.