光明在书中。把书完全打开，让它发光，让它发挥作用。

The only sensible ends of literature are, first, the pleasurable toil of writing; second, the gratification of one's family and friends; and lastly, the solid cash.

解释：曲子高妙，不是人人都能和唱；说出真相，不是人人都能相信。