In science, read, by preference, the newest works; in literature, the oldest. The classic literature is always modern.
Poetry should help, not only to refine the language of the time, but to prevent it from changing too rapidly.
Some books are to be tasted, others to be swallowed, and some few to be chewed and digested.
I know many books which have bored their readers, but I know of none which has done real evil.