And, Aristotle gave us this system, which persisted almost through the Middle Ages. And, Aristotle gave us this, and I'll leave you with this.

他带给我们这个系统，一直统领着我们,直到中世纪，亚里士多德给了我们这个，你们自己看吧。

麻省理工公开课 - 固态化学导论课程节选

One of the best descriptions I've ever read of why slavery persisted, of why people defended it, and why people went to war for it, came before the war, in 1857, in a speech by the African-American woman, novelist, writer, poet Frances Ellen Watkins Harper.

我曾读到的一段比较精彩的论述,关于为什么奴隶制度留存了下来,为什么人们为其辩护,为其而战,在1857年,战争前夕,在一个非裔美国女人的演讲中,她是小说家兼作家兼诗人,弗朗斯·伊莲·瓦特金·哈伯

耶鲁公开课 - 美国内战与重建课程节选