The trouble with the etymology of theory and the way in which the word has been used traditionally is that sometimes it actually means practice, and then at other historical periods it means something very different from practice, something typically from which practice is derived.

理论这个词在词源,和传统的使用方法上的复杂之处在于,它有时候指的是实践，但在特定的历史时期,它指的是和实践非常不同的东西，也就是实践产生的依据。

耶鲁公开课 - 文学理论导论课程节选

These are pictures of two notoriously good men, Oskar Schindler and Paul Rusesabagina, each who at different times in history saved the lives of many, many people at great risk to themselves.

这是些众所周知的好人的照片,奥斯卡·辛德勒和保罗·卢斯赛伯吉纳,两人在不同的历史时期,冒着生命危险挽救了很多人的生命

耶鲁公开课 - 心理学导论课程节选