I can't sell myself into slavery any more than I can take somebody else's life or take someone else as a slave by force.

不能将自己变卖为奴隶,我也不能剥夺他人生命，或胁迫他人成为奴隶。

耶鲁公开课 - 公正课程节选

You cannot say to me, "Take a force, due to a spring, and see what force it applies and divide by the acceleration and get the mass, " because we haven't defined force, either.

你不能说,"给弹簧施加一个力,看看它能提供多大的力,然后除以加速度,得到质量",因为我们还没给力下一个定义

耶鲁公开课 - 基础物理课程节选