The primary rules of obligation are those that require or forbid certain actions.

美是你内心的感受，它会反映在你的眼睛里。它不是物质的东西。

The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.

借助显微镜，没有什么小到能逃过我们的探究；因此，一个新的可见世界被揭示给了我们的理解。

We must, however, acknowledge, as it seems to me, that man with all his noble qualities still bears in his bodily frame the indelible stamp of his lowly origin.