《历史的教训》

“人”，是天文时刻中的一瞬，是地球上进门就走的过客，是物种的细胞，是种族的接穗，是一个由身体、性格和思想搭起的积木，是家和组织的一份子，是信仰的追随者或怀疑者，是一个经济单位，是一个国家的公民，一支军队里的士兵。

以此对应：“历史”，就是分别在天文学、地质学、地理学、生物学、人类文化学、心理学、道德、宗教、经济、政治、和战争中，来解释“人”显露出的本性、做过的事、和对未来的预期。

（Since man is a moment in astronomic time, a transient guest of the earth, a spore of his species, a scion of his race, a composite of body,character, and mind, a member of a family and a community, a believer or doubter of a faith, a unit in an economy, perhaps a citizen in a state or a soldier in an army, we may ask under the corresponding heads – astronomy, geology, geography, biology, ethnology, psychology, morality, religion, economics, politics, and war-what history has to say about the nature, conduct, and prospects of man.）