“Even four harnessed horses cannot bring imprudent words back into the mouth.”

“Writing cannot express all words, words cannot encompass all ideas.”

“You cannot open a book without learning something.”

“The gem cannot be polished without friction, nor man perfected without trials.”

“Music produces a kind of pleasure which human nature cannot do without.”

“The book salesman should be honored because he brings to our attention, as a rule, the very books we need most and neglect most.”

“When it is obvious that the goals cannot be reached, don't adjust the goals, adjust the action steps.”