地球提供了足够的东西来满足每个人的需求，但不是每个人的贪婪。
——1993年诺贝尔和平奖演讲
If one only wished to be happy, this could be easily accomplished; but we wish to be happier than other people, and this is always difficult, for we believe others to be happier than they are.
测量可测量的，并使不可测量的成为可测量的。