The only service a friend can really render is to keep up your courage by holding up to you a mirror in which you can see a noble image of yourself.

Every age has its massive moral blind spots. We might not see them, but our children will.

长期来看，只有真正创造价值的人才能生存。

在科学中听到的最令人兴奋的短语，预示着新发现的，不是“我找到了！”而是“这很有趣...”

可持续性不是一种趋势；而是我们对地球和未来农民的责任。