我们在自然知识中前进得越远，就越发现最普遍的定律是最简单的。
Happiness in this world, when it comes, comes incidentally. Make it the objet of pursuit, and it leads us a wild-goose chase, and is never attained. Follow some other object, and very possibly we may find that we have cought happiness without dreaming of it.
Look at a day when you are supremely satisfied at the end. It's not a day when you lounge around doing nothing; it's a day you've had everything to do and you've done it.