有两样东西,人们越是经常持久地对之凝神思索,它们就越是使内心充满常新而日增的惊奇和敬畏:我头上的星空和我心中的道德律。
So we beat on, boats against the current, borne back ceaselessly into the past.
Mathematics is not a spectator sport. You have to do it to understand it.