We cannot know the cause, and therefore the effect, by reason alone.

The greatest art is to make the invisible visible.

我必须研究政治和战争，以便我的儿子们可以自由地研究数学和哲学。

在观测天文学中，耐心是关键，有些发现需要几十年才能确认。

It is a far, far better thing that I do, than I have ever done; it is a far, far better rest that I go to than I have ever known.

可持续性不是一种选择；它是农业未来的必需品。